☻Digestive system

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DIGESTIVE SYSTEM

I-ORAL CAVITY

Many surgical diseases can interfere with an animal’s ability to prehend and transfer food material to the esophagus. The cause of dysphagia can be a congenital abnormality or diseases acquired through pain and/or mechanical obstruction.

I-DENTISTRY

Anatomy: -

The teeth are hard white or yellowish white structures implanted in the alveoli of the bones of the jaws. Functionally the teeth serve mainly as organs of prehension and mastication. The domesticated mammals have two sets of teeth. The first set appears during early life and is known as deciduous or temporary teeth. The second set appears later in life and is known as permanent teeth. Teeth are: Incisors, Canine, and Cheek teeth (premolars and molars). In male horse, there are four canine teeth while in the mare they are usually absent or rudimentary. In ruminants the canine teeth are absent. In dogs four canine teeth are well developed. Cheek teeth (premolars and molars) are located caudal to the canine teeth and embedded in the maxilla of the upper jaw and the mandible of the lower jaw. 

COMPOSITION OF THE TOOTH

A-The Pulp Of The Tooth

Is a soft, gelatinous tissue located in the central part of the tooth; the pulp cavity. The pulp consists of blood vessels, nerves and lymphatics with primitive connective tissue holding these structures. At the apex of the root is an apical foramen for passage of these vessels and nerves.

B-Dentine

Is a modified bone, forms the bulk of the tooth and covering the surface of the pulp. It consists of 30% organic contents and has dental tubules which pass to the pulp cavity. Dentine has some sorts of innervations.

C-Enamel

Is a hard, dense and white structure covers the crown of the simple tooth from the neck to the exposed tip. In complex tooth the enamel and cementum extending along the entire length of the tooth and are invaginated into the central part of the tooth forming the infundibulum or cup in the incisors and upper cheek teeth in equines. Enamel is the hardest substances in the animal body. It has only 2% organic contents and has no innervations.

D-Cementum

Is a bone-like tissue without havarsian canals which covers the dentine at the level of the root in simple tooth, but exists in a large quantity, to fill in the spaces between enamel folds of the crown in complex tooth.

E-Peridontal Ligament

It is a modified periostium consists of dense connective tissue with collagen bundles connect the cortical bone of the alveoli (lamina dura) with cementum. It is responsible for cushioning mechanism of the teeth. Each simple tooth has three parts; the crown, which is the projected or exposed part of the tooth above the gum; the root, the embedded part of the tooth, and the neck, the demarcation between these two parts which is located at the gum line. The complex tooth consists of long body and very short root or roots. The body has a free portion, which protrudes from the gum and an embedded portion, commonly called the reserve crown. With continuous wear of the occlusal surface, in equine and cattle, the reserve crown erupts from the gum line and becomes the free portion of the tooth. The root is usually short and has within it an apical foramen or foramina. In dogs, once the teeth are fully erupted, tooth development ceases except in the laying down of dentine on the inside of pulpal surface. The surface of the tooth directed towards the lips is termed "labial, towards the cheek "buccal", and towards the tongue" lingual and palatal. The surface opposed to the neighboring tooth is termed "contact surface". The masticatory or occlusal surface is that facing the opposite dental arcade. In dogs, mesial and distal refer to surfaces of the teeth that face towards and away from the medial plane, respectively. Anterior teeth are the incisors and canines lying in the rostral aspect of jaws, while posterior teeth are the premolars and molars positioned caudally. Apical and coronal are terms for a direction of the teeth towards the root or crown, respectively.

Dental formulae (PERMANENT TEETH)

Horse and donkey: 2 (I 3/3, C 1/1, PM 3-4/3, M 3/3) = 40-42

Cow, sheep goat:   2 (I 0/4, C 0/0, PM 3/3, M 3/3) = 32

Camel: 2 (I 2/4, C 1/1, PM 2/1, M 3/3) = 34           

Dog: 2 (I 3/3, C 1/1, PM 4/4, M 2/3) = 42

Cat: 2 (I 3/3, C 1/1, PM 3/2, M 1/1) = 30 

1-CONGENITAL ANOMALIES OF THE TEETH

A-Anodontia

Definition: -

It is the absence of teeth. It can be either total (no teeth is present) or partial (one type of teeth is absent). Congenital absence of teeth is more common in the permanent dentition than in deciduous dentition. No treatment is recommended.

B-Oligodontia

Definition: -

It is the presence of a reduced number of teeth.

1-Pseudo-oligodontia

It occurs most frequently due to impaction of one or more teeth in the jaw. The radiographic examination may be necessary for a definitive diagnosis.

2-True Oligodontia

It occurs due to either an absence of tooth bud and known as reductive oligodontia or destruction or suppression of the tooth bud during embryonic life and known as sporadic oligodontia. Oligodontia is usually without any symptoms and treatment is not indicated. Only sequelae are treated. Abnormal elongation of the opposing tooth should be regularly shortened or floated to prevent damage to the oral mucosa.

C-Polydontia (supernumerary teeth)

It is the presence of extra or supernumerary teeth in addition to the normal number. The extra tooth may crowd other teeth causing malposition, malocclusion or incomplete eruption of adjacent teeth and periodontal disease. Supernumerary teeth are generally incisors and molars. Frequently supernumerary molars are just posterior to the third molar and quite often on both sides. Polyodontia is classified into two types

Pseudopolyodontia: Is the retention of some or all deciduous teeth beside or behind the permanent teeth. Pseudopolyodontia can be observed also when different kinds of teeth come abnormally close together gives an impression of presence of additional number such as canine tooth occurring directly adjacent to the third incisor.

True polyodontia: This form is a true malformation in which there is an increased number of tooth germs or resulted from division of one tooth germ. The extra tooth may possess the characteristics of deciduous or permanent tooth (typical polyodontia) or exhibit a simple conical shape (atypical polyodontia).

Clinical signs: -

1-Injuries of the gum and soft tissues in the mouth cavity

2-Entrapment of food materials between the supernumerary tooth and the normal adjacent one which may leads to periodontal disease.

Treatment: -

1-Extraction of the retained deciduous tooth

2-In horses and cattle, when the true extra-teeth wear more or less evenly and cause no apparent trouble, they should be left without extraction and when the extra-teeth elongate and interfere with the occlusal surface of the arcade they should be shortened or extracted.

3-In dogs no extraction is recommended except by owner’s request

D-Diastasis Dentium

This condition is characterized by presence of a space between two neighboring teeth. It is frequently observed in horses, donkeys, and dogs and less common in cattle

Causes: -

1-Congenital causes

1-Failure in the position of the tooth bud during embryonic stage of development

2-Torsion or rotation of the tooth during development

3-Presence of supernumerary tooth which leads to formation of a space between it and the normal one

2-Developmental causes

1-Retention of one deciduous tooth

2-Impaction of one permanent tooth

3-Extraction or missing of one tooth

Clinical signs: -

1-Presence of a space between two neighboring teeth

2-Entrapment of food materials in these spaces and putrefaction may take place resulting in periodontal disease.

Treatment: -

1-Frequent brushing of the teeth and removal of accumulated food materials

2-Removal of supernumerary tooth or retained deciduous tooth

E-Brachygnathism (parrot mouth or over shot bite)

Definition: -

It is a congenital anomaly in which the upper jaw is longer than the lower jaw. The mandible lies in an excessively caudal position in relation to the upper jaw. The mandibular incisors are lingual to their maxillary counter parts.

Clinical signs: -

The upper incisors protrude more than halfway past the occlusal surface of the lower incisors, in such case the lower incisors develop hooks on their lingual border. In severe cases there may be no contact at all between the occlusal surfaces of the incisors, resulting in elongation of all incisors due to absence of wear. This condition causes wounds or ulceration of the gum. Difficulty in prehension of food is observed and affected animals may exhibit gastro-intestinal disturbances and general emaciation.

Treatment: -

1-Rasping of the sharp hooks in slight cases using tooth rasp

2-In severe cases frequent shortening of the lower incisors with special tooth cutter is indicated

3-In complicated cases the extraction of the lower incisors may improve the animal's condition and lessen the trauma to the soft tissues of the upper jaw and mouth

4-Wounds and ulcerations of the gum are treated by daily irrigation with antiseptic and astringent solutions

F-Prognathism (pig mouth or under shot bite)

Definition: -

It is a congenital anomaly in which the lower jaw is longer than the upper jaw.  The mandibular incisors lie labial to their maxillary counter parts. In dogs, the mandibular canines lie mesial to the maxillary third incisors.

Clinical signs: -

The same signs as in brachygnathism except that the upper incisors are responsible for troubles in soft tissues at the lower jaw.

Treatment: -

The same as in the brachygnathism. In slight cases the sharp hooks are rasped and in severe cases frequent shortening of the upper incisors or complete extraction is indicated.

2-DEVELOPMENTAL ANOMALIES OF THE TEETH

A-Sharp Enamel Points (sharp teeth)

This condition is characterized by formation of a sharp enamel points at the buccal aspect of the maxillary arcade and lingual aspect of mandibular arcade. Sharp enamel points are a common condition in horses and donkeys.

Causes: -

1-Anatomically, the lower jaw is 30% narrower than the upper jaw. The maxillary cheek teeth are set more laterally than the mandibular cheek teeth thus the palatal maxillary aspect and buccal mandibular aspect are subjected to more wear

2-Restricted movements of the jaw due to a painful lesion in the mouth, weakness of the masseters and inflammation of the mandibular joints.

3-Type of food and unequal hardness of the teeth

Clinical signs: -

1-Presence of sharp enamel points at the buccal aspect of the maxillary arcade and the lingual aspect of the mandibular

2-Wounds and lacerations at the cheek, tongue and gum

3-Difficulties during mastication and quidding of the food

4-Swelling of the cheek due to accumulation of food between the teeth and cheek

5- Bad general condition of the animal and weight loss as a result of anorexia and/or improper mastication followed by progressive emaciation and weakness.

Treatment: -

1-Regular rasping of the cheek teeth (floating of teeth) using tooth rasp or tooth float.

2- Touch the wounds with antiseptic solution or Tr. of iodine.

B-Step-formed Teeth (step mouth)

It is the presence of abrupt variations in the height of the adjacent teeth.

Causes: -

1-Unequal hardness of teeth substance

2-Defective growth of one tooth (Hypodontia)

3-Distortion or rotation of one tooth

4-Extraction or shedding of a tooth and consequent over growth of the opposing one

5-Fracture of a tooth (splintered or transverse fracture)

6-Presence of supernumerary tooth (Polyodontia)

7-Projection of a tooth

8-Elongation of a tooth

Clinical signs: -

1-Presence of abnormal variations in the height of the cheek teeth

2-Falling of food materials from the mouth mixed with saliva

3-Bad mastication with general emaciation and weakness of the animal

Treatment: -

1-Removal of the projections by tooth rasp or float

2-Shortening of long tooth by using dental cutter

C-Projection Of The Tooth (Hooking)

This condition affects equine and cattle. It is characterized by the presence of a small or large hook at the rostral point of the first upper cheek tooth and caudal point of the sixth lower cheek tooth. The hooked tooth may reach double the length of normal tooth. This condition is usually accompanied by parrot mouth. Hooking may develop in any tooth not subjected to equal wear

Treatment: -

Removal of the projected part by dental cutter and rasping it by tooth rasp

D-Elongation Of Tooth (Exsuperantia dentium)

This condition affects equine and cattle only. It is characterized by overgrowth of the whole tooth and usually observed when the opposite one is missing or when a supernumerary tooth is present and become elongated due to absence of another one on the opposite arcade. The tooth becomes longer because it is not worn away. It also grows faster because of the lack of masticating pressure.

Treatment: -

Frequent shortening of the elongated tooth by using a tooth cutter or regular rasping by tooth rasp to control overgrowth

E-Retained Deciduous Tooth

The deciduous tooth is retained and prevents the permanent tooth in that location to erupt. The permanent tooth may erupt close to the retained one and may cause change in the direction of the eruption, crowding or malocclusion. Retained deciduous premolar teeth are identified by eruption of the permanent one covered with the deciduous tooth (dental caps). This condition is observed in animals with signs of mastication difficulties. Caps remain attached to the permanent teeth after these teeth have been erupted for variable time. Caps should be removed once the permanent tooth has grown beyond the gingival line. It is best not to attempt to remove caps if it requires a great deal of effort to lossen them.

F-Impaction Of A Tooth (Delayed eruption of a tooth)

It is the failure of a tooth to erupt due to presence of a barrier in the normal eruption pass way. This condition is not uncommon in dogs and rare in other animals. A completely impacted tooth is recognized by its absence in the dental arcade but its presence radiographically.

Causes: -

1-Lack of space

2-Presence of a deciduous tooth

3-Misalignment of the tooth bud

Treatment: -

1-When radiographic examination revealed presence of the impacted tooth under the level of the gum, the gingiva should be splitted to allow the crown to emerge.

2-Extraction of the impacted tooth is dictated when the impaction is affecting the position or causing resorption of the roots of the permanent teeth adjacent to it or if they are causing abscessation.

G-Attrition In Dogs

It is the rapid loss of the crown height in dogs. Slight wear is considered normal, however attrition is abnormal. Diet and chewing habits count for most instances of severe attrition. Grooming is a major function of the incisor teeth in dogs. Pathological grooming as in cases of flea bite dermatitis may wear the teeth completely down to the gingivae. The dental pulp responds to rapid wear by lying down reparative dentine, which is visible as a dark brown mark on the affected teeth. Sometimes, the rate of wear is too rapid for the reparative process to keep pace with, and pulp exposure occurs.

Treatment: -

It is usually not necessary unless pulp exposure has occurred.

H-Changes in the shape of the teeth

Developmental anomalies in the shape of teeth are rare and of little clinical significance.

I-Dichotomy

Ii is the division of a single tooth bud resulting in a single root with two crowns.

J-Gemination

It is the joining of two normally separate tooth buds.

K-Dilaceration

It is an abnormal sharp curvature of the root of tooth.

3-DISEASES OF THE TEETH

A-Dental Tartar Or Dental Calculi (Odontolithiasis)

Definition: -

It is a salivary concretion that accumulates on the dental surfaces.

Causes: -

Soft and convenient diets given to animals contribute to the build-up of food debris on the surface of the teeth. The first stage in the formation of deposits is called dental plaque. The later consists of a soft, light-colored amorphous mass formed of food debris, leukocytes, microorganisms and desquamated epithelial cells. The second stage is mineralization of the dental plaque. It takes place through calcium and phosphorus salts present in the saliva. The soluble calcium bicarbonate which present in the saliva is converted into insoluble calcium carbonate with release of CO2 and its deposition inside the plaque resulting in formation of dental calculus.

Signs: -

Dental tartar produces no clinical signs but in severe cases it may cause the following:

1-Offensive fetid bad breath

2-Localized inflammatory reaction at the gingivae which termed gingivitis

3-Gingivitis results from mechanical irritation caused by the calculus and from endotoxins librated from the bacterial plaque. The gum is red with swollen gingival margin which bleed easily to the touch.

4-Periodontal disease may supervene if treatment is not carried out.

5-Dental calculus varies in color from grayish-white to grayish –brown. It has a rough surface which encourages further build-up of plaque.

6-The common seats of calculus formation are the lingual surface of the incisors especially that of the lower jaw, around the canines and the buccal surfaces of premolar and molar teeth.

Treatment: -

1-Hand scaling: It is the removal of soft and mineralized plaque from the surfaces of the teeth as atraumatically as possible to leave a smooth surface which discourages the build-up of the further deposits. The sharp edge of the tooth scaler is placed apical to the calcified deposits and moved by pulling action in a coronal direction. The process is repeated around the circumference of each tooth until the deposits are removed.

2-Mechanical scaling: Hand scaling is time consuming and ultrasonic device is used for rapid removal of deposits.

3-Large calculi can be dislodged by inserting a special dental instrument between the tooth and calculus and exerting a gentle pressure.

4-The mouth cavity is washed with mild antiseptic solution as potassium permanganate.

5-The stains of the teeth are removed by using 3% H2O2 or 1% HCl. 6- The inflamed gum is swabbed with Tr. of iodine or glycerine/iodine combination. Tr. Myrrh or catechu can be used.

6-Dogs must be given raw meat and bones.

7-Periodical brushing 2-3 times a week is essential for dogs using nylon brush and special tooth paste that has a meat flavor to encourage dogs to accept them.

B-Periodontal Disease

Definition: -

It is the inflammation and/or degeneration and destruction of the soft and hard tissues which surrounds and supports the teeth.

Causes: -

Complicated cases of dental tartar lead to periodontal disease. In periodontitis, the epithelial attachment of the gingivae migrates apically (recession of the gum) and periodontal ligament and alveolar bone will be destroyed. Enzymes such as protease, collagenase and elastase play a major role in the breakdown of the periodontal tissues, as collagen is the main component of the periodontal ligament and alveolar bone. The sources of enzymes are the microorganisms and/or the leukocytes. Spaces often developed between the teeth and gums called periodontal pockets, which in turn harbor further microbial irritants.

Signs: -

1-Bad breath, yellow teeth and facial swellings

2-Gingivitis and ulceration of subgingival epithelium

3-Recession of the gum (apical migration of the gum)

4-Loss of attachment between periodontal tissues and the tooth

5-Tooth mobility and spontaneous exfoliation of loose teeth may occur

6-Osteoclastic resorption of the marginal alveolar bone

7-Abscessation of the periodontal and periapical tissues may occur and exudates may come from beneath the gingival margin

8-Pulpitis, evidence of pain and difficulty in mastication

9-The condition may lead to pathological fracture or dental fistula.

10-Toxins will constantly be liberated into the blood stream and play an important role in the etiology of endocarditis, nephritis and hepatitis

Diagnosis: -

1-Clinical signs

2-Inspection of gingival sulcus with a thin calibrated periodontal probe. Animals with pockets deeper than 3 mm may have peridontitis

3-Radiography

Treatment: -

Periodontal disease is a multi-faceted condition. Usually, there is no simple, single therapy to alleviate the condition. Periodontal treatment is divided into two equally important areas;

Professional treatment: -

This includes scaling, polishing, elimination of any stagnation area and extractions. The purpose of professional periodontal treatment is to remove the irritants from the surfaces of the teeth and create an environment that helps in the control of future build-up of these deposits. Scaling is done by removal of calcified deposits from the teeth. It must be carried out systematically with a full understanding of the underlying pathology, objectives and limitations of the treatment. Careless scaling may lead to irreversible damage to the surfaces of the teeth which will only exacerbate the periodontal disease. Correct scaling and polishing will leave the surfaces of the teeth smooth, which discourage the build-up of further deposits. Polishing is essential to eliminate the microscopic scratches that have been created. Gingivectomy can be beneficial in eliminating false pockets as in the case of hyperplastic gingivitis. This simple surgery can eliminate the dead space of a pocket which harbors debris, bacterial plaque … etc. In advanced cases of periodontal disease, extraction of the teeth is the treatment of choice.

Home care and maintenance: -

The utilization of dietary and artificial oral hygiene aids by owners. The successful periodontal treatment of domestic animals lies with their owners, who have to be motivated to take an active step in the care and maintenance of the animal’s oral health. Motivational factors may be one or all of the following; cost of anesthetics and scaling, risks of general anesthesia for daily maintenance, bad smell and level of halitosis will be reduced and tooth conservation. Diet is an essential factor for self-cleaning action. Soft diet encourages plaque formation. Also, bone is not an ideal cleaning material. Dry bet food with large pieces of fibrous meat, in the form of an ox heart or ox tail can have a considerable self-cleaning action on the teeth. Brushing teeth is an important way of reducing bacterial plaque.

C-Dental Caries

Definition: -

It is a progressive, localized and circumscribed decay or disintegration of the tooth substance (enamel, dentine and cementum) with subsequent formation of a hole, which increased in width and depth until reaches the pulp cavity producing endodontic disease. Dental caries observed in horses more than in dogs.

Causes: -

1-Presence of a small fissure at the wall of the tooth and invasion of acid-forming microoganisms which are present normally in the mouth cavity. The effect of acids leads to disintegration of the tooth substance, especially the enamel

2-Softening of the substance of the tooth by decomposed saliva and fermented food materials which accumulated at the cement cavity (infundibulum) of the tooth

3-Entrapment of food materials at the spaces between the teeth and its fermentation

4-Hypoplasia of the enamel

5-Deficiency of trace elements and vitamins

Signs: -

1-Dental caries started by appearance of a yellow spot which changed quickly into brown or black color at the neck of the tooth or at the contact surface of the tooth or at any place where the fissure or hypoplasia of the enamel was present (enamel flecks).

2-Formation of a hole after disintegration of the tooth substance

3-Formation of large tubular defects that extend to the pulp and root apex causing secondary pulpitis, periodontitis, dental fracture

4-Severe pain when drinking a cold water and during mastication due to accumulation of food materials at the hole and its pressure over the content of the pulp cavity

5-Offensive odor from the mouth

6-Cemental or infundibular caries (cemental necrosis) develops within the infundibulum and usually progressed to reach the pulp.

Treatment: -

1-When dental caries is present near the root or contact surface or when pulpitis and periodontitis are present the tooth cannot be saved and "Extraction'' using tooth extractor is the only treatment.

2-Repulsion was performed when extraction was impossible.

3-In small defects and when caries is present at the occlusal surface, filling of the tooth is recommended. The necrotic tissues and decayed portion of the tooth are removed from the defect by drill or tooth burr. The cavity is washed and cleaned by hydrogen peroxide solution then dried by sterile paper points. Then the cavity is lined by copper cement and filled with suitable filling material (Amalgum). Zinc oxide and euginol may be applied as a sedative at the depth of the cavity before filling with amalgam.

D-Pulpitis

It means pyogenic inflammation of the dental pulp

Causes: -

1-Fissures and fractures in the crown of the tooth expose the pulp cavity to bacterial invasion

2-Dental caries and exposure of the pulp cavity

3-The senile and presenile erosion of one or more tooth

4-Abnormal wear due to bad habits as cribbing

5-Dental periodontitis

6- Hematogenous infection

Clinical signs: -

1-Severe pain due to acute inflammation of the pulp with difficult mastication

2-Percussion of the affected tooth is painful

3-The tooth is dead and the pulp is no longer sensitive to stimuli

Treatment: -

Extraction of the tooth involved.

E-Dental Fistula

It is a purulent tract connecting between the alveolus of the affected tooth and the outside surface of the skin.

Causes: -

1-Alveolar periostitis

2-Abscess at the root of the tooth

Clinical signs: -

1-Fistual opening at the level of the upper jaw in dogs and lower jaw in horses

2-The opening is small funnel-shaped, discharging pus with very foetid odor

3-Swelling of the bone and skin around the fistula opening

4-Metal probe is passed through the canal, striking the root of the tooth, and a hell-like sound is heard

Treatment: -

1-Extraction of the involved tooth

2-Curetting of the fistula and washing with antiseptic solution

N.B. : -

Fistula resulting from a splintered fracture of the mandible or maxilla may be misdiagnosed as dental fistula and known as false dental fistula. It characterized by short canal and small opening; there may be more than one, dull sound by metal probe, the inflammation of the bone around the opening is slight, discharged pus is small in amount and not very bad smelling, and the teeth are healthy. It is treated as fistula in general.

II-ORAL CAVITY SOFT TISSUE AFFECTIONS

1-LACERATIONS

The soft tissues of the oral cavity are susceptible to traumatic injuries by harness bits, sharp external objects, blows to the head, injury during recovery from general anesthesia, and iatrogenic damage during intra-oral procedures. The lacerations may involve the lips, buccal membranes, and the tongue. Animals usually present with excess salivation, which may be mixed with blood, decreased appetite, and various degrees of dysphagia, depending on the severity of the laceration.

The oral cavity soft tissues have a tremendous capacity for repair. Most superficial lacerations heal without surgical intervention by using daily mouth lavage and systemic antibiotics and by feeding a soft diet.

A-Tongue Lacerations

Lacerations of the tongue are not uncommon and can be severe, with transverse lacerations more frequent than longitudinal ones. The free portion of the tongue is usually involved because this part has more exposure to the external environment. Clinical signs include oral hemorrhage, inappetence, anorexia, dysphagia, malodorous breath, pyrexia, and tongue protrusion from the mouth. Management of tongue lacerations is guided by the severity, duration, and location of the injury.

Treatment: -

1-Superficial wounds of the tongue heal well due to bacteriostatic effect of the saliva as well as good blood supply of the tongue.

2-Deep wounds and lacerations are sutured with non-absorbable suture material with obliteration of dead space within the tongue substance.

3-Partial glossectomy is reserved for cases in which the rostral tongue tissue is devitalized and minimal attachment is left between the severed section and the remaining body. Tissue color, temperature, and evidence of bleeding at an incision can be used to assess viability. Partial glossectomy works well in horse, pig, sheep and goat up to 10 cm from the apex without causing feeding disturbances. In cattle because of the tongue’s crucial role in prehension of food, as much of the tongue as possible should be preserved.

Partial glossectomy

The animal is anesthetized and placed in lateral recumbency. A tourniquet (made of rolled gauze) is applied proximal to the intended transection site. The lingual artery and vein are tied on each side of the ventral middle portion of the tongue at the level of amputaion.

The tongue is divided in a V-shaped fashion, the base of the V pointing towards the tongue root. The tips of the two triangular arms of the tongue are brought together with one interrupted silk stitch. Then a line of silk stitches starts at the point of amputation at the dorsal surface and runs forward, over the point of the tongue, and along the ventral surface backward to the point of amputation again. Only mucosa is incorporated in the suture. The tourniquet is removed. The animal should receive systemic antibiotics postoperatively and should be fed a soft diet (not pasture) for best results.

B-Buccal Cavity Laceration

Partial-thickness buccal cavity lacerations are managed by second-intention wound healing with oral lavaging after meals and nonsteroidal anti-inflammatory drugs. Large, full thickness injuries may be reconstructed to prevent oro-cutaneous fistula development. Repairing the oral aspect of the wound is difficult because of limited space. Suturing the wound from the external side, starting with the mucosal layer, is more practical.

C-Lip Lacerations

When there is major disruption, surgery is indicated to preserve lip function and cosmetic appearance. The wound edges are prepared routinely by sharp debridement and lavage. First-stage healing is best achieved by the construction of intraoral mucosal flaps to achieve an oral seal. The skin is apposed with simple interrupted sutures.

2-STRANGULATION OF THE TONGUE

Causes: -

1-Tying of a string around the tongue as a mean of control in horses or tying of a cord around the lower jaw and tongue for a period of time

2-Strangulation of the tongue by a rounded foreign body such as rubber rings, tracheal rings and piece of large blood vessel in dogs.

Treatment: -

1-Removal of string or foreign body early as much as possible

2-Scarification of the dorsal surface of the tongue

3-Partial glossectomy if necrosis of the tongue has been occurred

3-SELF-SUCKING IN CATTLE

In ruminant kept for milk production, some animals learn to self-suck. This will result in a loss of large quantities of milk as well as high incidence of mastitis within these animals.

Treatment: -

Self-suckling is most commonly treated by using a nasal ring with a burr and individual housing. If these more conservative treatments are not successful, a partial glossectomy can be considered.

Partial Glossectomy

Two surgical techniques have been created to perform a partial glossectomy to prevent self-suckling in animals. The techniques are performed with sedation and local infiltration of lidocaine. Both techniques alter the tongue’s contour to prevent the animal from forming a U-shaped tongue for suckling. For the ventral glossectomy technique, an elliptical incision is made that is approximately 5 cm at its widest part and starts rostral to the frenulum attachment on the tongue and extends rostrally 2.5 cm caudal to the tip of the tongue. Each side of the ellipse is incised at an angle toward the midline to facilitate closing the defect. The lateral glossectomy technique removes half of the tip of the tongue. Again, the incision is extended at an angle to facilitate closing the tongue.

4-ORAL CAVITY FOREIGN BODIES

Various types of metallic, usually linear, foreign bodies can penetrate the soft tissues of the oral cavity after inadvertent ingestion. Plant matter, such as grass awns or wood splinters, is also a frequent cause of foreign body reaction. External clinical signs include focal or diffuse intermandibular, retropharyngeal, and facial swelling, depending on where the foreign body has lodged or what it is migrating through. Swellings typically have increased heat, and the animal has evidence of pain to palpation of them. Ptyalism, dysphagia, inappetence, and anorexia can be observed. Additionally, there may be a painful response and difficulty when attempts are made to open the jaw. Oral and oropharyngeal examinations can reveal firm, painful swellings, the end of the foreign body, or ulcerated mucosal surfaces where the foreign body has penetrated the tissue, or where an abscessed site has ruptured spontaneously.

Diagnosis: -

It requires a combination of thorough history taking, external and oral examination, and imaging aids. Radiography is helpful for metallic foreign bodies, but care must be taken not to miss a fine, short structure. Ultrasonography is very useful to help pinpoint the exact location of a foreign body.

Treatment: -

The treatment of choice is removal of the foreign body. Surgical approaches may have to be creative. An external approach to a foreign body that has migrated into the deep part of the masseter muscle requires care to avoid trauma to facial nerve branches, parotid duct, and blood vessels in that region. Foreign bodies associated with intraoral swelling may be approached by incising the mass on the oral side and draining exudate into the mouth. Digital or instrumental exploration and debridement of the cavity can then be performed. The cavity is lavaged and allowed to heal by second intention. Postoperative care may consist of a combination of oral lavaging, necrotic tract lavaging, and antibiotic and anti-inflammatory therapy.

5-GLOSSOPLEGIA (PARALYSIS OF THE TONGUE)

Glossoplegia means paralysis of the tongue. It results from uni- or bilateral paresis or paralysis of the hypoglossal nerve (12th cranial nerve – purely motor).

Causes: -

1-Central paralysis results from encephalomyelitis (rabies, brain tumor, and sever intoxication).

2-Peripheral paralysis results from contusion, pressure, strain and torn of nerve along its course.

Signs: -

1-In bilateral paralysis, the whole tongue is flaccid and hangs out of the mouth at the center of the lips.

2-In unilateral paralysis, the tongue deviates towards the affected side when extended and towards the unaffected side when retracted.

3-Salivation is extensive. Mastication and swallowing of food are difficult or impossible.

4-At early stages of glossoplegia the tongue is unchanged but later on may develop secondary mucosal injuries, either self-inflected or from external trauma.

Treatment: -

1-Protection of the prolapsed part of the tongue from injury if it is possible

2-Injection of nerve tonics such as vitamin B-complex

3-Paralysis extends for more than 14 days has a poor prognosis. Sacrification may be indicated

II- SALIVARY GLANDS

Anatomy: -

The salivary glands are grouped into:

-Minor salivary glands

-Major salivary glands

A-Minor or small salivary glands

They are present in the mucosa of the lips, cheeks, tongue, palate and the sublingual oral floor. These glands produce a mucous secretion. The buccal minor salivary glands form larger aggregates ventrally and dorsally. In canines the latter is referred to as zygomatic gland, based on its position. Ruminants have an additional middle group of buccal glands. The majority of saliva is produced by the major salivary glands. These are located at a distance from the oral cavity and drain through ducts.

B-Major salivary glands

-Parotid salivary gland

-Mandibular salivary gland

-Sublingual salivary glands

1-The parotid salivary gland

It is a paired organ, which lies at the junction of the head and neck, ventral to the auricular cartilage in the retromandibular fossa. The parotid duct (Stenson's duct) opens into the oral vestibule at the top of a small papilla opposite the third to fifth cheek tooth depending on the species.

2-The mandibular salivary gland

It is located close to the angle of the jaw and is partially covered by the parotid salivary gland. It is slightly bigger than the parotid salivary gland in most dogs and cats. In carnivores it is oval in shape, situated subcutaneously, caudal to the monostomatic salivary gland between the linguofacial and maxillary veins. It drains by a single large duct, which passes ventral to the mucosa of the floor of the oral cavity, close to the lingual frenulum to open with the major sublingual duct on the sublingual caruncle.

3-The sublingual salivary glands

They consist of two glands on either side except the horse, in which the major (monostomatic) sublingual salivary gland is absent. The major (monostomatic) salivary gland is situated more caudally and is a compact gland with a single draining duct The major sublingual salivary duct shares a common opening with the mandibular salivary duct on top of the sublingual caruncle. The diffuse minor (polystomatic) salivary gland is located more rostrally and opens through several smaller ducts. These openings are located on a longitudinal fold in the lateral sublingual recesses.

I-SALIVARY MUCOCELE (SIALOCELE OR SALIVARY CYST)

Definition: -

Salivary mucocele is a collection of saliva that has leaked from a damaged salivary gland or salivary duct, and has accumulated in the tissues.  This is often noted as a fluctuant, painless swelling of the neck or within the oral cavity. While often inaccurately called a salivary cyst, mucoceles are lined by inflammatory tissue (called granulation tissue) which is secondary to the inflammation caused by the free saliva in the tissues, while a cyst is lined by epithelial (glandular) tissue which is itself responsible for the production of the fluid. Salivary mucocele is the most common salivary gland disorder of dogs but are very rarely in cats. While any of the salivary glands may be affected, the sublingual and mandibular glands are involved most commonly.  Salivary mucocele may be classified as follows: 

1-Cervical Mucoceles

This is probably the most common type of mucocele.  It is a collection of saliva in the upper neck region, at the angle of the jaw, or between the mandibles.

2-Sublingual Mucoceles (Ranula)

Another frequent location for the formation of a mucocele is on the floor of the mouth alongside the tongue. This is frequently seen in association with a cervical mucocele.

3-Pharyngeal mucoceles 

This type of mucocele is much less common. The fluid accumulation is almost entirely within the throat (pharynx).

Causes: -

The cause of salivary mucoceles is rarely identified, although trauma is generally considered to be the most likely initiating event. As the saliva leaks from the torn salivary gland or duct, it accumulates in the tissue and initiates an intense inflammatory response. A connective tissue capsule gradually forms around the saliva to prevent it from migrating further.

Signs: -

1-Cervical mucocele is seen as a gradually enlarging soft, painless, fluctuant mass in the upper cervical (neck) or mandibular (between the jaws) region.  In most animals there are no problems associated with the development of the mass.

2-Sublingual mucocele (ranula) the dog may have some difficulty eating and may develop bleeding from trauma to the mucocele as the dog chews.

3-Pharyngeal mucocele is generally totally undetectable until the oral cavity is examined with sedation. The animal may present with respiratory distress because the mass developing in the throat is beginning to obstruct the airways. This is a potentially very serious problem and treatment must be instituted rapidly because these animals may die from acute respiratory distress. Dysphagia (difficulty swallowing) may be another sign that a pharyngeal mucocele is present.

Diagnosis: -

1-Palpation of the mucocele is easily accomplished, and with the exception of the pharyngeal mucocele, the mucoceles are easily identified as a soft, fluctuant, painless mass that must be differentiated from abscesses, tumors, and other retention cysts of the neck.

2-A salivary mucocele usually can be diagnosed by aspiration of the characteristic golden or blood-tinged, viscous saliva.

3-Occasionally cervical mucoceles migrate to the ventral midline making it difficult to determine whether the problem involves the left or right sided glands. Examining the animals with sedation in dorsal recumbency often allows the mucocele to migrate to the affected side; if not, sialography may be helpful.

Treatment: -

The only satisfactory treatment for a salivary mucocele is removal of the salivary gland or glands that are involved with the mucocele. Surgical removal of the mandibular and sublingual glands on the side of the mucocele is the normal surgical treatment. The glands are removed together because the duct of the mandibular gland travels through the sublingual gland and removal of one gland would unavoidably traumatize the other.

Sublingual mucoceles (ranulas) may be treated with marsupialization (in addition to removal of the mandibular and sublingual glands) to facilitate drainage into the oral cavity.  Marsupialization is performed by excising an elliptical portion of sublingual mucosa overlying the mucocele and suturing the rim of oral mucosa to connective tissue

EXCISION of mandibular & sublingual glands

1-The surgical removal of the mandibular and sublingual salivary glands and their duct requires general anesthesia.

2-Wide clipping of the mandibular and cervical areas, and preparation for an aseptic surgery. The dog is positioned in lateral recumbency.

3-A linear incision is made from the angle of the jaw to where the linguofacial vein and the maxillary vein meet to form the jugular vein. The platysma muscle is divided, and the common capsule of the mandibular and sublingual glands is identified deep to the veins.

4-The capsule is opened, and the mandibular gland is grasped with an instrument. Caudolateral traction is carefully applied while sharp and blunt dissection gland. All these major vessels require ligation.

5-The dissection is carried to the digastricus muscle rostrally

6-The common salivary duct is ligated as far rostral to the termination of the sublingual salivary gland as possible

7-A quarter-inch Penrose drain may be placed to drain the primary incision

8-Closure consists of absorbable interrupted sutures in the platysma muscle or subcutaneous tissue, and skin closure

9-The drain may be removed in 3 to 5 days

10-Complications can include seroma formation, and local infection

II-SALIVARY CALCULI (SIALOLITH)

A sialolith is a calcified stone within the salivary ducts. The parotid duct is the most commonly involved. Sialolith is seen more often in equines and also recorded in cattle, dogs and camels. The sialolith is formed of an organic nucleus, surrounded by concentric layers of calcium phosphate crystals.

Causes: -

An ascending foreign body (such as spicules of grass), cellular debris or sloughed epithelial cells act as nidus for deposition of calcium salt.

Signs: -

1-Nonpainful, movable, firm structure is palpable on the lateral aspect of the face near the rostral end of the facial crest. In some cases, the sialolith may be palpable orally.

2-Obstruction of the duct is often incomplete, and saliva may continue to pass around the sialolith. However, with more severe obstruction, back pressure may cause duct and gland distention.

3-Reddening at the parotid papilla

4-Difficulty masticating, quidding, and decreased appetite

5-Calculi vary in size from cherry size to a fist

Diagnosis: -

1-Clinical signs

2-Metal probe inserted into the ostium of the duct strikes hard stone like structure

3-Radiography

Treatment: -

1-Definitive treatment is by removal of the sialolith

2-Smaller calculi may be massaged out of the parotid papilla. The use of lubricant oil may facilitate its removal.

3-If this is not possible, and the calculus is near the papilla, direct intraoral incision over the sialolith, leaving the wound to heal by second intention, is preferred.

4-Calculi inaccessible by the intraoral route must be removed by external longitudinal incision of the duct.  Cannulation of the parotid duct via the parotid papilla can be helpful to locate the exact calculus position and then may act as a stent for suturing the duct if primary closure is performed. The entire duct and gland should be lavaged with sterile polyionic solution. Closure of the duct with a simple interrupted or continuous pattern of fine absorbable suture material. Postoperative care is antibiotics and lavage of the duct and gland via catheterization of the oral papilla are recommended in infected cases.

III-SALIVARY FISTULA

It is abnormal tract connecting the salivary duct or gland to skin surface. Because of their superficial location, the parotid salivary gland and duct are more subject to traumatic injury than the two other, more deeply located glands.

Causes: -

1-Trauma to the side of the face

2-Previous surgical treatment of an abscess or calculi

Signs: -

A watery fluid is found to discharge through an opening in the skin at or near the lower border of the jaw. The quantity will depend upon the size of the opening and also upon the act of mastication. When feeding, the secretion of saliva is most active and the flow is very considerable, but becomes comparatively slight when food ceases to be taken.

Diagnosis: -

1-Clinical signs

2-Retrograde catheterization of the duct

3-Retrograde contrast radiography of the duct

Treatment: -

1-Repair the fistula

Excision of fistulous tract by a circular incision around the fibrous wall. Introduce a polyethylene tube (catheter) into the duct. Pull the tube until it is wholly in the duct and then push it in the reverse direction until it slides past the fibrous opening in the duct, toward the gland. Secure the end in the mouth by suture. Close the wound where the fistula has been excised in several layers with catgut. The skin wound is closed with simple interrupted silk suture. The catheter supports the suture line and prevents stricture development while maintaining saliva flow till wound healing.

2-Creation of intra- oral fistula (marsupialization)

A sharp needle or trocher penetrates the cheek (at the level of fistula) to the oral cavity. A strong silk thread is passed through the opening and the two ends are knotted at the commissure. The thread is kept in position until a permanent fistula is formed. The thread is then removed and the external opening of the duct and skin are sutured.

3-Destruction of the function of the gland

The alternative approach to managing a chronic parotid salivary duct fistula is to attempt to eliminate saliva secretion. This may be performed by surgical removal of the gland, duct ligation proximal to the fistula, or chemical ablation of the gland.

The gland may be injected with a caustic agent to destroy all secreting cells until the fistula resolves and heals. Use of 10 to 15 ml of Lugol’s iodine or up to 35 ml of 10% buffered formalin injected through a catheter placed into the duct.

IV-ECTASIA OF THE PAROTID DUCT

It is a dilatation of the parotid duct

Causes: -

1-Congenital

2-Obstruction by a foreign body lodged at the orifice of the duct

3-Obstruction by salivary calculi

4-Scaring of the orifice at the papilla 

Signs: -

1-The duct is dilated to the size of a thumb over the entire course

2-The swelling is soft and having the consistency of engorged vein

3-The dilated duct may reach the fest size in buffaloes.

Treatment: -

1-An attempt to pass a probe through the orifice of the duct

2-Incision of the narrow orifice with special scalpel

3-Creation of artificial intra-oral fistula (marsupialization): 1-2 cm long incision is performed in the oral mucosa and passed through the dilated duct. This artificially created internal fistula will provide an outlet for continuous salivary drainage. The constant secretion prevents healing of the fistula.

V-SIALADENITIS 

Definition: -

Inflammation of the salivary gland

Cause: -

1-Trauma from penetrating wounds

2-Systemic infection affecting the salivary gland or surrounding tissue

3-Systemic viral disease as canine distemper

4-Retrograde infection through the parotid duct

Signs: -

1-Fever, depression, and painful, swollen salivary glands

2-Rupture of an abscessed gland discharges pus into the surrounding tissue or the mouth

3-Rupture through the skin may cause a salivary fistula to form

Treatment: -

1-Abscess should be drained through the overlying skin

2-Systemic antibiotics should be administered

III-AFFECTIONS OF THE ESOPHAGUS

Anatomy: -

The esophagus is the tube between the pharynx and the stomach. At its origin it passes to the left of the trachea, so that at the thoracic inlet it comes to lie on the left lateral aspect of the trachea. Within the thoracic cavity it is located dorsal to the trachea and runs in the mediastinum, continuing beyond the tracheal bifurcation and over the base of the heart. It continues ventral to the ascending aorta with a slight dorsal inclination and enters the abdominal cavity through the esophageal hiatus of the diaphragm. It passes over the dorsal border of the liver to join the stomach at the cardia. Since it traverses most of the neck, all of the thorax and ends on entering the abdomen it is divided into cervical, thoracic and abdominal portions. The esophagus has four layers; these are (from the inside to the outside); Mucosa, Submucosa, Muscular layer, Adventitia  in the cervical portion and serosa in the thoracic portion (pleura) and abdominal portion (peritoneum)

I-OBSTRUCTION OF THE ESOPHAGUS

Obstructive esophageal disease, or choke, is frequently occurred in cattle and buffaloes.

Causes: -

1-Intra-luminal obstruction by foreign bodies.

2-Extra-luminal obstruction by peri-esophageal abscess, enlarged mediastinal lymph nodes or tumors

Signs: -

1-Signs of complete obstruction

1-Anorexia and ptyalorrhea (saliva dripping from the mouth because of inability to swallow).

2-The animal keeps the neck stretched and may swing the head from side to side with repeated attemps to swallow.

3-Severe tympany develops soon after complete obstruction

4-The patient remains thirsty and makes attemps to drink water, which often returns back through the nostrils

5-In cervical esophageal obstruction, a swelling at the left side of the neck can be seen and palpated.

2-Signs of incomplete obstruction

1-Anorexia and dysphagia may be observed

2-Bloat may occur repeatedly and resolved spontaneously or after passage of a stomach tube.

Predilection seats of esophageal obstruction: -

1-At the pharyngeal entrance, as the opening of the esophagus is bigger than the lumen

2-At the thoracic entrance.

3-At the level of the aortic arch, as the aorta and trachea limit esophageal distension.

4-At the cardia, where sphincter tone diminishes the lumen.

Diagnosis: -

1-Case history

2-Clinical signs

3-Palpation of the foreign body (in cervical obstruction)

4-Introduction of stomach tube

5-Plain and contrast radiography

Differential diagnosis: -

1-Rabies must always be considered when dysphagia is present and appropriate precautions were taken.

2-Tetanus may be similar to esophageal obstruction as a result of presence of bloat dysphagia and drooling

3-Ingesion of several poisonous plants may cause extensive salivatin, drooling and bloat

4-Pharyngitis

Treatment: -

It must be born in mind that complete obstruction of the esophagus in ruminant prevents eructation. This results in sever bloat and a cannula should introduce immediately into the rumen to provide continuous escape of gases.

Treatment is divided into three categories; medical treatment, manipulative treatment, and surgical traetment.

1-Medical treatment

1-Drugs used to reduce muscular spasm as tranquilizer

2-Fluid therapy to compensate fluid losses. Sign of acidosis should be treated by addition of sodium bicarbonate to the infusion fluid.

2-Manipulative treatment

1-It might be possible to clear the cervical obstruction by placing the thumb or fingers distal to the palpated foreign body and gradually forcing it upward until it reaches the pharynx and then can be removed by hand from the pharynx.

2-A stomach tube can be used to gently push  the obstructed forgein body into the rumen. However, such a method may be of value only if the obsructed foreign body is a round smooth object. Moreover, there is also danger of shifting the obstruction from the cervical to the thoracic esophagus.

3-The foreign body can be extracted by means of foreign body extractor under effect of tranquilizer

3-Surgical treatment

A-Surgical exposure of cervical esophagus without esophagotomy

1-Ventrolateral exposure occurs between sternocephalic muscle and trachea in the upper two thirds of the neck in large ruminant and equine. In sheep and goat the exposure of the esophagus is performed by ventrolateral exposure technique along the whole length of the neck

2-Lateral exposure occurs between the jagular vein and brachiocephalic muscle or between jagular vein and sternocephalic muscle in the lower one third of the neck in large ruminant and equine.

3-The exposure of the cervical esophagus is performed by the ventral exposure technique along the whole length of the neck between the two sternohyoid muscles.

After exposure of the esophagus, attemps are made to push the foreign body by direct manipulation, towards the pharynx (external taxis).

B-Esophagotomy

The stomach tube is placed to the level of the obstruction prior to anesthesia. The neck is prepared for aseptic surgery. After approaching the esophagus, the affected area is isolated from the surgical field using moist sponges. The left carotid sheath, containing the carotid artery and vagus and recurrent laryngeal nerves, should be retracted laterally. Care should be taken to preserve the small vessels that supply the esophagus. The esophagus is incised, and the foreign body is removed. The incision should be made in healthy esophageal tissue if possible. Where the incision is made into the esophagus depends on the mobility of the foreign body within the lumen and the amount of swelling in and compromise to the esophageal wall.

After removal of the foreign body, if the esophagus has a normal appearance in the area of the incision, closure should be completed. Primary esophageal closure involves a 2-layer technique. The mucosa and submucosa are closed together in either a simple continuous or simple interrupted pattern. A nonabsorbable (e.g., polypropylene or nylon) or longlasting absorbable (e.g., polyglactin 910, polydioxanone, or polyglyconate) suture material is used. It is recommended the knots be tied within the esophageal lumen to prevent contamination of the wound by ingesta migrating along suture tracts. The muscular layer can be closed by using either an absorbable or non-absorbable non-capillary suture with a simple interrupted or mattress pattern. A suction drain is placed beside the esophagus and exits ventral to the skin incision through a small stab wound. This drain is maintained under constant suction for 48 hours to remove serum and blood from the surgical site and to provide early detection of salivary leakage.

Postoperatively, food and water are withheld for 48 hours after surgery, and maintenance intravenous fluid therapy is instituted. Most esophagotomy incisions heal by first intention, and the intra-luminal suture will slough into the lumen within 60 days. If the esophageal wall is compromised, it should be allowed to heal by second intention with daily wound care.

II-ESOPHAGEAL STENOSIS OR STRICTURE

It means narrowing of the esophagus. It may be obstructive stenosis or compression stenosis.

1-Obstructive stenosis

It caused by fibrous tissue formation in the wall of the esophagus itself due to:

1-Deep damage to the esophageal wall following removal of a foreign body.

2-Local pressure necrosis of the mucosa

3-Esophageal perforation

4-Severe esophagitis due to caustic anthelminitics or gasroesophageal reflux of HCL

5- Following esophagotomy operation

2-Compression stenosis

It is not caused by fibrous tissue formation in the wall of the esophagus as in:

1-Neoplasia and abscessation in the wall of the esophagus

2-Peri-esophageal swelling as abscess, neoplasia or enlarged lymph node

Signs: -

1-Signs of esopgageal obstruction

2-Accumulation of food at the seat of stricture

3-Dilatation of the esophagus cranial to the stricture site which is palpable in cervical esophagus

4-Stricture impedes passage of stomach tube but narrow tube might pass.

Diagnosis: -

1-Clinical signs

2-Contrast radiography

3-Endoscopy

Treatment: -

1-Surgical removal of the cause of narrowing

2-Partial resection

3-Complete resection and anastmosis

4-Esophagoplasty

III-ESOPHAGEAL DIVERTICULUM

There are two types of esophageal diverticulum, and both are usually acquired conditions.

1-Traction (true) diverticulum

It results from contraction of periesophageal fibrous scar tissue, often secondary to a wound or previous surgery. Traction diverticula are usually asymptomatic because its wide neck does not entrap feed, and it retains sufficient musculature to transmit normal peristalsis.

2-Pulsion (false) diverticulum

It results from protrusion of mucosa and submucosa through a defect in the esophageal musculature. These diverticula may result from external trauma, fluctuation in esophageal intraluminal pressure, and overstretch damage to esophageal muscle fibers by impacted foodstuffs. Affected animals are often dysphagic but able to drink. They may regurgitate after eating. The diverticulum may enlarge over time and become evident as a large swelling in the neck, which results in dysphagia or choke. Esophagoscopy helps define the relative size of the opening of the diverticulum.

Diagnosis: -

1-Clinical signs

2-Contrast radiography

Treatment: -

1-Traction diverticulum, even when quite large seldom requires treatment.

2-Pulsion diverticulum can be repaired by diverticulectomy with resection of the mucosal-submucosal sac, followed by reconstruction of the mucosa, submucosa, and muscularis, or by inversion of the mucosal-submucosal sac with reconstruction of the muscular layer.

Diverticulectomy should be used when the mucosal sac is very large and the neck of the diverticulum very narrow. However, mucosal inversion is the preferred technique because it decreases the chance of postoperative leakage, infection, or fistula formation.

IV-ESOPHAGEAL PERFORATION OR LACERATION

Causes: -

1-Esophageal perforation or rupture is caused most often by overzealous use of an instrument to dislodge an obstruction.

2-The foreign body itself can also cause pressure necrosis of the esophageal wall.

3-Other causes include pharyngeal trauma, extension of a soft tissue infection, and cervical trauma.

Signs: -

1-Affected animals usually develop impressive subcutaneous emphysema. They are inappetent and depressed.

2-Swelling develops at the site of the rupture and can progress to a sizable infection of the surrounding area.

3-Migration of infection down fascial planes to the mediastinum and thoracic cavity can be catastrophic.

Diagnosis: -

1-The diagnosis can be confirmed with esophagoscopy, ultrasound, or a contrast radiographic study.

2-On survey radiographs, irregular gas opacities may be detected in the soft tissues of the neck, surrounding the esophagus and trachea, and/or within the mediastinum.

3-If esophagraphy is performed, iodinated contrast medium should be used. If the esophagus is perforated, contrast medium is detected in the soft tissues outside the esophagus.

Treatment: -

1-Tissues healthy enough to be closed after esophageal perforation are rare, but primary closure can be attempted with a lesion less than 12 hours old.

2-Closed suction drainage should be used to avoid serum and blood accumulation at the surgical site.

3-Therapeutic antibiotics, nonsteroidal antiinflammatory drugs, and tetanus prophylaxis are administered.

4-If primary closure is not possible, ventral drainage is provided, and the wound is allowed to heal by second intension. Adequate ventral drainage is mandatory to prevent septicemia and cellulitis, extending along fascial planes and causing lower airway disease or possibly generalized septicemia.

5-The patient can be fed via a rumen fistula. Healing these tissues can be a long, drawn-out process and is rarely warranted.

V-ESOPHAGEAL FISTULA

It means presence of fistulous tract connecting the lumen of the esophagus with the skin at the left side of the neck

Causes: -

Esophageal fistulae may result from healing esophagotomy incisions or after esophageal perforation.

Signs: -

Presence of an opening discharge food, water and saliva. This discharge increase during eating

Diagnosis: -

1-Clinical signs

2-Contrast radiographs.

Treatment: -

Resection of the fistulous tract and closure of the stoma

VI-MEGAESOPHAGUS

Segmental or generalized dilation of the esophagus. This disorder is usually described in young animal that have an atonic esophagus that accumulates solid food that may occlude the esophagus. However, some cases may be described in an adult animal.

Signs: -

Affected animals are dysphagic, salivate, and cough. Aspiration pneumonia is common.

Diagnosis: -

Regardless of age, survey radiographs reveal air or an airfluid interface within an atonic esophagus. Esophagraphy shows a large accumulation of contrast material in the esophagus.

Treatment: -

Treatment is supportive. Animals should be frequently fed small amounts of easily digestible feeds.. Antibiotics are indicated for pneumonia.

The prognosis is unfavorable.

IV-AFFECTIONS OF STOMACH & INTESTINE

I-RUMENANT STOMACH

1-RUIMINAL IMPACTION

Primary rumen impaction occurs in buffaloes and cattle mostly with depraved appetite. Most of these animals eat plastics, ropes leather pieces and cloths that make large tight ball inside the rumen due to churning movements to cause impaction.

Signs: -

1-Tympany

2-Anorexia

3-Leather pieces can produce obstruction at the reticulo-omasal orifice and most of them were recovered from the reticulum.

Treatment: -

1-Rumenotomy is performed to remove impacted materials. The churned up mass is difficult to remove as such and has to be cut into pieces.

2-Correction of the rumen pH and addition of ruminal fluid from healthy animals speed up the recovery process

3-yeast tablets (50 tab) can be kept inside the rumen. Also, administer 20 yeast tablets orally twice a day for 2-3 days to revive the normal fermentation process in the rumen.

2-TRAUMATIC RETICULOPERITONITIS (TRP)

It means penetration of the wall of the reticulum by a hard object resulting in localized reticulitis and peritonitis.

Incidence: -

The condition is common in house-holding buffaloes and cattle in Egypt. Nearly more than 10% of animal are affected with traumatic reticulo-peritonitis.  20-25% of buffaloes and cattle have metallic foreign bodies in their reticulum. Incidence of the condition is very low in foreign countries because of better awareness by livestock raisers. Also, administration of magnet reduces the incidence of the condition in these countries. TRP is mostly found in middle and old aged animals. It is considered a disease of dairy cattle and buffaloes. Condition is very rare in camel and small ruminants.

Causes: -

1-Sewing needles

They are the most dangerous foreign body swallowed by animals. 95% of extracted needles during rumenotomy were found penetrating and in many instances were recovered from the heart at necropsy findings.

2-Hair clips

Also a dangerous foreign body recovered from many animals affected by TRP. The sharp end of one prong was found penetrating while the other blunt end was found bearing weight on the reticular wall.

3-Nails

They are the most common metallic object recovered from the reticulum. Our results in some studies performed on the varieties and sequelae of ingested foreign bodies indicated that only 30% of nails were found penetrating the reticulum.

4-Wire pieces

In governmental and private farms, feeding bales are sometimes tied off by wire. Feed cutters often cut accidentally baling wire into short pieces and offered to animals with food.

5-Other types of sharp metal objects

They are rarely causing TRP in animals. Most of them cause injuries and wounds to the reticular mucous membrane without penetration.

6-Nutritional deficiencies

Many animals seek out for metals in an attempt to tolerate their craving.

7-Bad management

Bad management and bad hygienic conditions which lead animals to grass on unsuitable places as seat of garbage collections around cities.

Animals usually take these foreign bodies accidentally and because the process of mastication is not complete, foreign bodies are quickly swallowed. In addition, papillae of the tongue are directed caudally ad thus prevent the animal to get red easily of these foreign bodies.

Clinical signs: -

1-The onset of the signs is usually sudden

2-Capricious appetite

3-Milk yield is significantly diminished

4-The head and neck are somewhat stretched

5-Thoracic kyphosis and lumbar lordosis are evident in some cases

6-Stiffness of the thoracic limb and abduction of the elbows

7-Lying down, standing and turning especially to the left are painful

8-Rumination is weak or absent

9-Feces are firm and decreased in quantity.

10-Temprature usually remains normal except when there is spreading peritonitis.

11-Heart beats and rate are normal.

12-Respiration is normal except when the rhythm is disturbed by grunting

13-Ruminal movements are normal or decreased

Diagnosis: -

1-Case history

2-Clinical signs

3-Pain tests; pole (stick) test, withers test, back test, percussion at the xiphoid region and going up and down a hill. These tests are used to detect the pain resulting from penetrating foreign body in cattle, and appear to be not satisfactory for buffaloes.

4-Hematological examination: Shift to left in WBC count – leucocytosis is variable with lymphopenia and neutrophilia.

5-Radiographic examination: plain radiograph of the caudal thorax and cranial abdomen is a useful diagnostic aid. Apart from locating foreign bodies, the radiographs also provide sufficient information concerning the nature and extend of the damage caused by potential foreign bodies.

6-Metal detector is a good mean for detection of metallic foreign bodies.

Disadvantages of metal detectors: -

  • It does not detect if the foreign body is penetrating or non-penetrating.
  • It does not detect if the foreign body is sharp or not.
  • It does not detect the accurate location of the foreign body.

Treatment: -

Surgical treatment by laparo-rumenotomy is the only serious surgical interference for correction of such cases.

Rumenotomy operation

Indications: -

It is the treatment of choice for TRP although it is indicated for many other conditions affecting ruminant stomach.

1-Frothy tympany

2-Ruminal indigestion (acid indigestion and alkaline indigestion)

3-Primary ruminal impaction

4-Ingestion of toxic plants

5-For diagnosis and differential diagnosis (exploratory laparotomy and rumenotomy)

6-Rumenotomy should be done early in the course of disease for best results especially in valuable animals

Anesthesia: -

1-Paravertebral analgesia

2-Local infiltration analgesia in the form of linear infiltration or inverted L

Preoperative preparation: -

1-Clipping and shaving of hair of the left flank region

2-Washing of the site of operation by warm water and soft soap

3-Application of antiseptic agent such as Tr. of iodine and alcohol

Techniques: -

1-Weingart’s technique

1-Left flank laparotomy, the incision is about 20-25cm in length and parallel to and caudal to the last rib by 5cm and below the transverse processes of the lumbar vertebrae by 5cm. The incision passes through; skin, subcutaneous tissue, external oblique abdominal m., internal oblique abdominlal m., transverse abdominal m. and parietal layer of peritoneum.

2-The Weingart’s ruminal frame is fixed at the upper commissure of the wound with screw.

3-A ruminal fold is grasped and fixed to the Weingart’s frame by two Weingart’s forceps.

4-A sterile towel is trapped between the exteriorized ruminal fold and the abdominal incision to avoid leakage of ruminal contents into the peritoneal cavity.

5-The right hand is introduced into the abdominal cavity to examine rumen, reticulum, spleen, left lobe of liver, kidneys, bladder, intestine and uterus.

6-The rumen is punctured by scalpel and the wound is widened by a scissors then the lips of the ruminal wound is fixed to the Weingart’s frame by 4 or 6 Weingart’s hooks.

7-Part of ruminal contents is evacuated and ruminal foreign bodies, if present, are removed then the hand is directed forwards, downwards and somewhat medially to reach the reticulum through the wide reticular orifice. Reticular foreign bodies either floating or penetrating are removed then the reticular cells are examined carefully for presence of any penetrating foreign body. Adhesions are detected and perireticular abscesses are located and drained to outside through a needle and polyethylene tube if they are large enough and soft, otherwise they are left without any surgical interference.

8-The cardia and the reticulo-omasal orifices are examined.

9-The hooks are removed and the ruminal wound is cleaned then sutured by double rows of inverting sutures using chromic gut No. 2 or 3.

10-The parietal peritoneum and transverse abdominal m. are sutured with simple continuous suture using chromic gut No. 2 or 3.

11-The internal and external oblique abdominal muscles are sutured with simple continuous pattern using absorbable suture material.

12-The subcutaneous tissue is sutured also with absorbable suture material in a simple continuous pattern.

13-The skin wound is sutured with simple interrupted, interrupted mattress or continuous interlocked suture using non absorbable suture material and a sharp needle.

14-A thin layer of cotton is applied to the skin wound

15-Sutures are removed 10 days post-operatively

2-Goetze’s technique

This technique can be performed without the use of special set for fixation of ruminal fold and edges. After laparotomy, the ruminal fold is exteriorized and sutured all around with the parietal layer of peritoneum to close the peritoneal cavity. The rumen is then incised and the edges of the ruminal wound are sutured to the skin. In addition, a special plastic manchette is applied to the seat of operation to reduce contamination of wound edges. After completion of operation, the manchette and skin sutures to the ruminal edges are removed, while the suture of parietal peritoneum to the ruminal fold is left.

Complications of TRP: -

1-Perireticular abscesses

2-Generalized peritonitis

3-Traumatic pericarditis

4-Traumatic pneumonia and lung abscess

5-Liver abscess

6-Intestinal rupture

7-Vagal indigestion

8-Diaphragmatic hernia

2-TRAUMATIC PERICARDITIS (TP)

Traumatic pericarditis results from penetration of a sharp foreign body into the pericardial sac. First of all, the foreign body penetrates the reticulum then the diaphragm and finely penetrates the pericardium inducing pericarditis. The condition is observed in cattle more than buffaloes and recorded mostly in pregnant animals at the latter stages of pregnancy or soon after parturition.

Signs: -

1-A history of complete anorexia, loss of body weight and reduction of milk-yield

2-Sudden appearance of mandibular and brisket edema filling and pulsation of the jugular vein

3-In some cases, edema of the thoracic limbs and ventral abdominal wall was clear.

4-Arched back and winged elbows were evident in many cases.

5-Auscultation revealed muffled heart sound and dyspnia, increased pulse rate and rise of body temperature up to 40C.

Diagnosis: -

1-Case history

2-Clinical signs

3-Pericardiocentesis revealed presence of purulent exudates coming out from the pericardial sac in jets with heartbeats. The seat of pericardiocentesis is in the intercostal space between the left fifth and sixth ribs just behind the elbow. A 10-12cm, 24-gauge-needle is used and suction with syringe is sometimes indicated.

4-Plain radiography of the thorax revealed poor differentiation of the thoracic contents. The contour of the diaphragm was lost and the cardiac silhouette was undifferentiated. In some cases the shadowgraph of metallic foreign bodies was seen at the level of the heart or in the area connecting the dome of the diaphragm with the heart.

Treatment: -

No treatment in such cases is indicated. It is recommended to send the animal to slaughterhouse.

3-OMASAL IMPACTION

Omasal impaction occurs mostly secondary to rumen impaction and is a result of poor quality feed. The omasum gets distended with stagnated ingesta. Omasal impaction usually discovered during rumenotomy operation. A very hard rounded mass was found right to the reticulum and rumen.

Signs: -

1-Anorexia, listless and signs of dehydration

2-Omasal sounds on auscultation are absent at the level of right elbow at the 9th intercostal space

Treatment: -

1-Administration of 4-5 liters of liquid paraffin or mineral oil to soften the contents through a stomach tube or laparorumenotomy incision

2-Tablets of yeast (50), 2-3 kg sugar, and 2-3 liters of ruminal fluid from healthy animal may also be added to stimulate the rumen flora.

3-Rumenotomy may be performed and a long tube with needle attached to a syringe may be used to inject solution directly into the omasum through the right ruminal wall.

4-Neglected cases proceed to a dangerous course and necrosis of omasal leaves may occur due to continuous pressure exerted by the impacted materials.

4-ABOMASAL IMPACTION

Seen in cattle and recorded in buffaloes. The primary cause is excessive consumption of poor quality indigestible roughages and inadequate mineral supplementation with restricted access to water. Foreign bodies, trichobizoars (hair balls), or phytobizoars (plant balls), and sand may also cause impaction. TRP, abomasal lymphosarcoma, fat necrosis and vagal indigestion may lead to abomasal impaction.

Signs: -

1-Complete anorexia

2-Scant feces

3-Marked dehydration

4-Moderate distension of abdomen

5-Lower right abdominal quadrant may appear distended giving a pear shaped appearance from behind

6-Reduction of milk yield

Treatment: -

1-Softening of impacted contents with lubricants

2-Intensive fluid therapy containing sodium chloride, potassium and calcium

3-Abomasotomy may be indicated to evacuate the contents

4-Slaughtering may be the ideal solution

5-ABOMASAL ULCER

It occurs in suckling calves and adult cattle and may cause gastric hemorrhage, indigestion, melena and in some cases perforation with local or diffuse peritonitis. Abomasal ulceration has also been reported in buffalo calves.

Causes: -

1-In high producing cows within first few weeks postpartum

2-In calves, it appears to occur when diet of low dry matter content (milk) is changed to high dry matter content (grass, grains and hay) suddenly

3-Trichobizoars (hair balls) are often present in calves with abomasal ulcers but it is not clear if trichobizoars cause the ulcers or found after ulcers have developed

4-Hyperacidity and increased mucosal permeability to hydrogen ions are requisite for ulcer formation

5-Abomasal ulcerations were seen in necropsy findings secondary to traumatic pericarditis, diaphragmatic hernias, vagal indigestion, abomasal displacement, abomasal foreign bodies and some cases of traumatic reticlo-peritonitis

Types: -

1-Erosion and ulcers with slight hemorrhage

2-Bleeding ulcers

3-Perforation with acute local peritonitis

4-Perforation with diffuse peritonitis

Signs: -

The clinical signs vary depending on the type of ulcer and whether are associated with hemorrhage or perforation.

1-Abdominal pain, melena, pale mucous membranes

2-Anorexia, ruminal stasis

3-Calves become recumbent suddenly with cold extremities

4-Tachycardia and dehydration then death occur within 24 hours in newly borne animals

Diagnosis: -

It depends mainly on clinical signs.

Treatment: -

1-Change of diet from high to low concentrates

2-Antacids such as magnesium silicate (100gm) or magnesium hydroxide/aluminum hydroxide 50ml 3 to 4 times daily administered orally for 2 to 3 weeks

3-In bleeding ulcers and perforation with local peritonitis, treatment is directed to control bleeding and injection of coagulants, antibiotics and adequate fluid therapy is recommended.

4-Radical excision of ulcerative patches following abomasotomy

6-ABOMASAL DISPLACEMENT

The abomasum is a wandering organ due to its loose attachments with the greater and lesser omentum. The organ can displace easily to the left (LDA) or to the right (RDA). LDA is more common than RDA and occurs primarily in cattle in countries where feed consists of high proportion of grains and other concentrates than roughages. In our locality no true case can be recognized up till now in cows or buffaloes. However, some Indian colleagues stated that displacement of the abomasum is very rare in buffaloes.

Incidence: -

1-In foreign breeds of cattle with large size and high producing milk in age group from 3-7 years

2-The highest incidence has been recorded 3 weeks anti-partum to 4 weeks postpartum

Etiology: -

The exact etiology of the disease is unknown. The following causes may be suggested.

1-Genetic factors

Large and deep abdominal cavity in foreign breeds

2-Mechanical factors

1-Enlarged gravid uterus during pregnancy. The rumen is lifted by gravid uterus and the abomasum may slide to the left under the rumen. Following parturition, the rumen will come to its normal position, while atonic and distended abomasum may get trapped between the rumen and left abdominal wall.

2-Lameness in the left fore or hind limb.

3-Right recumbency for hoof trimming

3-Physiological factors

1-Abomasal atony with increased gas production may act as a predisposing cause.

2-Feeding of high concentrate ration increases production of volatile fatty acids. Unabsorbed volatile fatty acids pass from the rumen to the abomasum and decrease the contractility of the latter. Accumulation of gases causes distension and displacement.

Signs: -

Usually appears as a result of grossly distended abomasum and partial obstruction of the digestive tract.

1-Loss of appetite, sudden drop in milk yield and dehydration

2-Decreased quantity of feces (scanty)

3-Ruminal movements are sluggish and weak

4-Auscultation of the left side area of the last three ribs reveals a gas distended structure and produce tympanic resonance sound (ping)

5-Bulge behind the last rib

6-Hypocalemia and hypochloremia

Treatment: -

The aim of treatment is the correction of displaced abomasum, restoration of the GIT motility, rehydration and correction of metabolic disorders.

1-Calcium preparation to stimulate the GIT motility

2-Administration of warm saline solution and mineral oil to help evacuation of contents

3-Intensive IV fluid therapy using balanced solution to correct dehydration

4-Surgical correction of displaced abomasum includes decompression, replacement to normal position and fixation of omentum or abomasum to the body wall to form adhesions so that recurrence does not occur by:

a-Left flank laparotomy and omentopexy or abomasopexy

b-Right flank laparotomy and omentopexy or abomasopexy

c-Ventral laparotomy and abomasopexy

d-Quick stitch method (Blind stitch)

II-EQUINE STOMACH

1-GASTRIC ULCER

Gastric ulceration produces signs of abdominal distress and may result in stomach perforation leading to fatal peritonitis. Formation of ulcers has been related to diet, race, training and stabling. It is usually clinically silent or develops as a result of colic and may lead to lake of condition, weight loss and poor performance.

Treatment is aimed to maintain gastric PH above 4 until ulcers have healed.

2-GASTRIC DILATAION

Gastric dilatation refers to the abdominal accumulation of fluid and gaseous ingesta that induces clinical signs of acute abdominal distress. Ingestion of foodstuffs that swell with moisture or fermentable food may lead to primary gastric dilatation. Volatile fatty acids formed by fermentation produce delay in gastric emptying, further exacerbating gas accumulation.

3-GASTRICIMPACTION

It means abnormal accumulation of dry, poorly fermentable ingesta in the stomach producing anorexia, dysphagia, mild colic and gastric pain.

Also non-nutritious feeds, irregular feeding, dental diseases, gastric atony and pyloric stenosis are additional causes of gastric impaction. Treatment to relief gastric impaction include; gastric lavage with nasogastric tube in the standing  horse with external massage of the stomach via a ventral celiotomy, hydration of the impaction by a tube or long needle passed directly into the stomach or manual removal of impacted food material after surgical approach.

4-PYLORIC STENOSIS

The causes of pyloric stenosis include congenital hypertrophic pyloric stenosis, acquired hypertrophic pyloric stenosis as a result of gastritis, muscular hypertrophy of the pylorus, gastric ulceration and formation granulation tissue. Clinical signs include weight loss, poor appetite, tooth grinding, salivation and gastric retention. Pyloric stenosis is relieved in young animals by pyloroplasty in which a full-thickness longitudinal incisions through the pylorus was closed transversely also the condition can be corrected by side-to-side gastroduodenostomy.

5-GASTRIC RUPTURE

Gastric rapture occurs at the greater curvature of the stomach with colic in horses. Grain overload, ulcerative gastritis, gastric impaction and nasogastric feeding may lead to gastric rapture. Also strangulating or nonstrangulating obstruction and adhesions have been reported as a cause of gastric rapture.

Gastric rapture is a fatal condition because of the gross contamination of the abdomen that occurs

III-CANINE STOMACH

1-GASTROESOPHAGEAL INTUSSUSCEPTION

It means that the stomach or part of it is herniated into the esophagus. Young animals are most frequently affected and it is often fatal condition.

Clinical signs include dyspnea, shock, vomiting, regurgitation, hematemesis, dehydration, abdominal pain and weight loss.

Diagnosis is usually confirmed by plain and contrast radiography and fluoroscopy. Radiographs reveal esophageal dilation and mass in the distal esophagus.

Treatment: -

Supportive therapy, emergency laparotomy and gastropexy to the left body wall

2-HIATAL HERNIA

It means protrusion or herniation of any structure mostly stomach, through the esophageal hiatus of the diaphragm. It may be sliding or paraesophageal forms.

Clinical signs include vomiting, dyspnea, hypersalivation, weight loss and signs of pneumonia.

Diagnosis is usually confirmed by radiography and fluoroscopy. Megaesophagus may be seen on plain radiography along with a gas-filled soft tissue density in the caudal thorax.

Treatment: -

1-Medical treatment

Dietary modification and administration of antacids

2-Surgical treatment

The goal of surgery is to return the lower esophageal sphincter and distal esophagus to the abdominal cavity and to close the esophageal hiatus. The operations performed are esophagopexy, gastropexy and diaphragmatic crural apposition.

3-PYLORIC STENOSIS

Is a congenital thickening of the pyloric sphincter that results in delayed gastric emptying of solid food.

Signs: -

Vomiting that usually starts after weaning and growth of the animal may be retarded.

Diagnosis: -

It is confirmed by contrast radiography, ultrasonography and exploratory laparotomy.

Treatment: -

It is surgical by either pyloromytomy or pyloroplasty

4-GASTRIC FOREIGN BODIES

Ingestion of foreign bodies becomes a significant problem when gastro intestinal obstruction or perforation occurs.

Signs: -

Frequent or intermittent vomiting as seen in pyloric obstruction

Diagnosis: -

It is confirmed by abdominal palpation and survey radiography. Contrast studies or endoscopy may also be useful.

Treatment: -

It is based on the size and the shape of the foreign body

1-Small objects may be expelled by induction of vomiting. Apomorphine and Xylazine have been used to induce vomiting in dogs and cats respectively.

2-Small foreign bodies with smooth surface can be extracted with grasping forceps during endoscopy.

3-Large or rough foreign bodies can be extracted by laparogastrotomy.

5-GASTRIC DILATATION AND VOLVULUS

It is a life-threatening condition in which the stomach becomes dilated and displaced along its long axis, permitting a gaseous distention from erophgia but prevent release of gases through the pylorus or esophagus.

Prolonged gastric distention compromises the intramural gastric blood vessels and compresses the portal vein and caudal vena cava. Reduction of the venous return to the heart from the caudal vena cava compression eventually results in hypovolemic shock with clinical signs of tachycardia, weak pulse, pale mucous membrane, hypothermia and collapse. Venous stenosis may lead to fundic ischemia, mucosal necrosis, endotoxic shock and death.

Signs: -

Restlessness abdominal distention ptyalism depression and signs of acute collapse

Diagnosis: -

Clinical signs and confirmed by radiography. Survey films reveal a displaced air-filled pylorus and gastric distention.

Treatment: -

1-Stomach decompression: the stomach is de compressed by orogastric tube, percutaneous gastrocentesis, or through gastrotomy.

2-Surgical derotation of the stomach and permit gastropexy to prevent recurrences.

3-Partial gastroectomy may be necessary in presence of non-viable portions of the gastric wall.

4-Splenectomy is necessary if splenic torsion and vascular thrombosis are present.

6-INTESTINAL OBSTRUCTION

It means interruption in the passage of the intestinal contents. Intestinal obstruction may be mechanical (physical blockage) or functional (altered motility due to dietary factors, enteritis, peritonitis,…etc) and may occur in any part from the intestine.

Classification: -

1-Acute or Chronic

2-Partial (stenosis) or complete

3-Simple (when the blood vessels are not involved) or strangulated (when the blood vessels are impaired).

Types of intestinal obstructions: -

A-Mechanical

1-Extra-luminal obstruction

a-Intussusception (invagination)

Invagination or telescoping of one part of the intestine into another part. It can occur at anywhere throughout the length of the intestine.

The invaginated part consists of outer, middle and inner layers and it may associate with enteritis or systemic illness. 

This condition commonly reported after environmental changes and intestinal surgery and common at the age less than one year.

Clinical signs vary with the level and the severity of the obstruction.

The case can progress to a point at which the small intestine protrudes from the anus (differentiated from rectal prolapse by the easy passage of a probe between the prolapsed segment and the rectum).

Plain radiograph show bowel distension with gases or fluids and   displacement of the abdominal organs.

The case may be manually reduced (if the blood vessels are patent and the wall does not look ischemic).

b-Volvulus

A life threatens rare condition, in which the intestine twists along its mesenteric axises causing obstruction and compression of the mesenteric artery and ischemic necrosis occurs.

Causes: -

1-Congenital long mesentery

2-Indigestion and colic

3-Violent movement and rolling

4-Irregular peristalsis

5-Unequal filling of the bowel

c-Strangulation

2-Intra-mural obstruction (tumor)

As a result of intestinal tumor in the wall of the intestine or hemorrhage

3-Intra-luminal obstruction

a-Foreign bodies

b-Sand (in horse)

In case of presence of sand within the bowel of a horse, x-ray shows radiopaque materials within the bowel.

c-Phytobezoars and triychobezoars

Bezoars are indigestable materials within the GIT (impair motility or cause intestinal obstruction).

Phytobezoars are indigestible food material while trichobezoar are hairball.

B-Functional

1-Ileus or Hypo-dynamic state (ileus)

Ileum is the absence of propulsive movement of GIT contents resulting in distension of the bowel distended with gases.

Thrombi and emboli (larva) within the mesenteric blood vessels cause ischemia and inability to contract.

2-Strangulation (incarceration)

A condition in which the intestine entrapped in a natural / artificial open in the mesentery or by pedunculated tumor

Strangulation arrests the bowel blood flow causing edema, cyanosis and gangrene

Pathophysiology of intestinal obstruction

In simple mechanical obstruction, blockage occurs without vascular impairment. The ingesta are accumulating above the obstruction and the proximal bowel distends and the distal segment collapses. The normal absorptive function is depressed, and the wall becomes edematous and congested.

Severe intestinal distention is progressive, intensifying the peristalsis and secretion and increase the risks of dehydration and progression to strangulation.

Strangulating obstruction is accompanied with impaired blood flow and can progress to infarction and gangrene. Venous obstruction occurs first, followed by arterial occlusion, resulting in rapid ischemia of the bowel wall.

The ischemic bowel becomes edematous and infarcts, leading to gangrene and perforation.

During obstruction, there is increased intestinal secretion and reduced absorption    leads to reduction in intravascular volume and dehydration that cause hypovolemic shock.

Profuse vomiting may cause less in CL, Na and K. and HCL causing metabolic alkalosis.

Loss pancreatic secretion (rich with Na, water and Hco3) leads to metabolic acidosis. 

Diagnosis: -

1-The history and signs

2-Physical examinations

3-Rectal examination

4-Radiography, ultrasonography and laparoscopy

Signs: -

Signs differ according to location, duration and severity of the obstruction;

1-General signs

Anorexia, less feces tinged with blood and mucous, abdominal distention, increased pulse, temperature may increase (become subnormal in late stages).

In equines; frequent laying and standing, sweating, looking to site of pain, kick on abdomen, and paddling of hind limbs (death occur within 24 hours).

Rectal examination; intussusceptions appears as a firm coiled mass. In case of volvulus and strangulation the intestine appears distended with gas and firm. In case of intestinal rupture with peritonitis; there is adhesion of the viscra.

In cattle; abdominal distension, straining, grunting, kicking on the belly, depressed back (death occur within 10 days).

Rectal examination; caecal dilatation and torsion palpated as a dome shaped structure on the dorsal right region runs to the ventral left region

In pet animals; vomiting, anorexia, weakness and weight loss and frequent attempt to defecate with tiny feces

In ovine; abdominal distention, anorexia, no faces.

General Principals Of Small Intestine Surgery

1-Fluid therapy:  -

-Fluids are essential to restore fluid and electrolytes balance.

-Balanced fluids and electrolytes are recommended.

2-Antibiotics:  -

They are recommended because;

-Stagnant contents and dead cells are good growth media for microflora.

-Opening of the intestine may causes leakage of contents and the contamination may results in peritonitis.

3-Assessment of intestinal viability:  -

Considering the color, peristaltic waves (Progressive wave-like contractions) and vascular pulsations

4-Choice of suture materials for closure: -

Monofilament absorbable ( polydioxnone, chromic catgut) or non-absorbable (nylon or polypropylene) suture materials

5-Choice of suture pattern: -

Submucosa is the strongest part and its apposition result in primary intestinal healing, so seromascular suture patterns (lambert and cushing) are recommended).

                                 

6-Surgical line reinforcement: -

Using the omentum which has an extensive vascular and lymphatic supply and has adhesive properties, it also control infection and restore blood supply and lymphatic drainage

 

 

 

 

SURGICAL TECHNIQUES FOR INTESTINAL SURGERY

1-Enterotomy

2-Enterectomy (Intestinal resection and anastomosis)

Surgical Anatomy: -

The duodenum is the most fixed portion of the intestine, the jejunum forms most of small intestine coils and lying in the ventrocaudal abdomen while the ileum has an anti-mesenteric vessel.

Blood supply of the intestine comes from mesenteric artery and gastro duodenal artery (which supply the cranial duodenum).

Nerve supply: Vagus and splanchnic nerves.

Anesthetic Considerations: -

Special consideration for cases of obstructions, ischemia or perforations

Enlarged viscera may disturb circulation (compression of vena cava) and disturb respiration (displace the diaphragm cranially).

Visceral manipulations may induce bradycardia.

1-Enterotomy

Opening of the intestine by incision and re-suturing of incised wound

Indications: -

Removal of an intra-luminal foreign body, biopsy, ….

Technique: -

Milk away the intestinal content from the site of obstruction. Apply intestinal forceps proximal and distal to the obstruction. The incision is done through the anti-mesenteric border just distal to the obstruction. The foreign body may be pulled by a forceps.

Enterotomy incision is closed longitudinally (may be closed transversely)

2-Enterectomy

It means intestinal resection and anastomosis, it can be performed by end to end, end to side, or side to side anastomosis

Indications: -

1-Ischemic or necrotic intestinal segments

2-Irreducible intussusception

3-Tumor

Technique of enteroectomy: -

1-The affected segment is clamped with intestinal forceps

2-The mesenteric vessels are ligated

3-The triangular piece of mesentery distal to ligature is torn and bowel is divided close to the clamp and removed                                                                              

Techniques: -                                                            Enterectomy

a-End to end anastomosis

There are several ways to suture small and large diameter intestinal segments:

1-Transecting smaller segment at an angle, creating a lumen of larger diameter

2-The smaller segment incised longitudinally in the anti-mesenteric border to create a larger opening. The first and second sutures are placed in mesenteric and anti-mesenteric borders

b-End to side anastomosis

The end of a small diameter viscus is sutured to the side of wider one

c-Side to side anastomosis

The two viscera are sutured side to side

 

 

 

 

 

 

           
   
     
       
 

 

 

 

 

 

Suture pattern for intestinal anastomosis: -

1-Single layer simple interrupted or simple continuous sutures

2-Single layer from inverting suture like as lambert or cushing pattern.

3-Parker Kerr suture technique: done as follow;

a-Continuous suture applied over clamp jaw

b-The free ends of thread pulled and clamp withdrawn

c-Then Lembert’s suture

d-Ends of stay suture are drawn out

Intestinal anastomosis is assessed through: -

1-Absence of leakage

2-Minimal lumen stenosis

3-Minimal adhesions

4-Rapid healing

Complications of enteretomy and enterectomy: -

1-Septic peritonitis

-Associated with dehiscence of anastomosis or enterotomy site.

-Clinical signs appear 2-5 days after surgery.

Treatment: -

Antibiotics, fluids, supportive therapy and surgical correction of the problem and complete drainage of the peritoneal cavity

2-Adhesions

-Dogs &cats have active fibrinolytic system prevents this adhesion

-Peritoneal irrigation with dialysis solution after surgery reduces this adhesion

3-Short Bowel Syndrome

-Mal-digestion and mal-absorption after extensive resection

4-Ileus

-A common complication

-Reduced motility due to over-activity of sympathetic system due to manipulation of intestine, long operative time and extensive resection

V-AFFECTIONS OF THE RECTUM

I-WOUNDS

It is common in domesticated animals

Etiology: -

It may occur as a result of; back racking, sever rectal impaction, dystocia, during overyectomy, and false introduction of penis in rectum during coitus, or sharp foreign bodies like needles in dogs.

Signs: -

Rectal wounds may superficial (limited to mucous membrane) or perforating

1-Painful defecation and bloody discharge

2-Injuries in the dorsal and lateral walls of the rectum may form an abscess or fistula around the anus

3-Wounds in rectal floor may leads to recto-vaginal fistula or peritonitis

Treatments: -

1-Superficial wounds treated by antiseptic infusion after evacuation of the rectum

2-Rectal and pre-rectal abscesses or fistula should be treated according to the principals that discussed in general surgery

3-Perforating wounds is treated through laparotomy

4-Recto-vaginal fistula will be discussed.

II-RECTAL PROLAPSE

It is common in young than adult animals

Forms: -

1-Mucosal Prolapse

The mucosa is protruded without muscular layers

2-Complete Rectal Prolapse

3-Complete Rectal Prolapse With Invagination

The anterior part of rectum is invaginated in a posterior part and both are prolapsed together

4-Complete Rectal Prolapse With Herniation Of The Intestine

A part from small intestine is invaginated in the pelvic portion of the rectum and both structures are prolapsed together

Etiology: -

1-Weakness of the anal sphincter

2-Severe diarrhea, infestation with gastrophilus larvae in equine (attach to the rectal mucosa causing straining)

3-Excessive straining and increase intra-abdominal pressure during colic, parturition, defecation, …

4-After casting the animal

Signs: -

1-Protruded rectum covered by mucous membrane which appears rosy red if the case is recent, while in old cases, ulceration, necrosis and bleeding may occur).

2-In severe cases; the rectum appears cyanotic, edematous and gangrenous.

Treatment: -

Differ according to the prolapsed part:

1-Reduction Of The Prolapsed Part

In recent cases, done under the effect of general or caudal epidural anesthesia.

The prolapsed part washed with normal saline and astringent like 2% alum (to reduce swelling) then reduced in its place and purse-string suture is applied.

The suture should be opened daily for evacuation of the rectum and removed completely after 7 days.

2-Shortening Of The Prolapsed Part Without Amputation

The idea of this technique is to remove the affected mucous membrane without damaging of the underlying tissue.

Performed if the prolapsed part is less than 15 cm and shows minimal pathological changes.

1-The rectum is packed with cotton tampon, and then slightly tracted to expose a healthy area and then fixed by two needles (20 cm long) inserted close to anus and crossing each other.

2-Two circular incisions (in the mucous membrane only) are made; the first at the apex, and the other one close to the base of the prolapsed part.

3-Another longitudinal incision connecting the two circular ones is performed and the incised part of the mucous membrane is bluntly dissected.

4-The proximal and distal ends of the healthy mucous membrane are sutured together along its circumference using catgut.

3-Amputation Of The Prolapsed Part

Performed if the prolapsed part is more than 30 cm and shows extensive pathological changes s necrosis or gangrene.

The hand is introduced into the rectum to exclude the presence of invagination or herniation which should be corrected at first.

The rectum tracted slightly to expose healthy area, fixed by needles (20 cm).

The double wall of the prolapsed part is sutured along circumference with interrupted Mattress using catgut.

The prolapsed part is amputated 3 cm anterior to the line of suture and the edges are sutured.

The operation is completed as mentioned.

III-RECTAL FISTULA (ano-rectal fistula)

It occurs as a complication of pre-rectal abscess, puncture rectal wounds

Forms: -

1-Complete Fistula

It has two opening, one at the rectum and other near the anus

2-Incomplete (rectal sinus)

a-Inner incomplete

It has one opening in the rectum.

b-Outer incomplete

It has one open opening around the anus.

Treatment: -

1-Washing with antiseptic and cauterization

2-Incision of the fistula without injuring the anal sphincter

3-Complete excision of the fistula and the resulted wound left to heal normally

IV-ANAL ATRESIA

Absence of anal opening resulted when the membrane separating the rectum and anus is failed to rupture.

The condition is discovered at birth by absence of anal opening and the animal shows abdominal pain, distension and no passage of feces.

Treatment: -

1-Circular skin incision is made over the protruded area at the anus

2-The skin disk is removed

3-The rectal wall is fixed in the surrounding by simple interrupted suture using silk

4-The rectum is punctured at its central part and evacuated

5-Skin suture is removed after 10 days

V-RECAL AGENESIS (rectal segmental aplasia)

It occurs when the rectum terminates before reaching the anus and it is usually accompanied by anal atresia.

Types of intestinal atresia: -

1-Type I Atresia

It is a mucosal blockage within the intestinal lumen

2-Type II Atresia

The proximal segment terminates in a blind end and the distal segment beings similarly with 2 ends being joined by a fibrous cord devoid of lumen

3-Type III Atresia

a-Type IIIa Atresia

It is similar to type II except that the proximal and the distal blind ends are completely separated and there is a mesenteric defect corresponding to the missing segment of intestine

b-Type IIIb atresia

It has a coiled distal segment of intestine

4-Type IV atresia

It involves multiple sites of atresia

Treatment: -

It is primarily surgical and includes

1-Cecostomy or suturing of the cecum to the abdominal wall in the form of fistula through which the animal defecates, when the anal opening is absent

2-Surgical excision of rudimentary part and re-anastomosis of the intestine when the anal opening is present