Inflammation is a complicated vascular and cellular reaction of an individual to an irritant that is not strong enough to cause death of tissue. The objects of inflammation are to destroy and remove the irritant, and to help in repair of the damage induced by this irritating agent.
Like trauma, blow, or sprain, all of these causes lead to rupture of certain cells and change of its phospholipids wall to arachidonic acid with subsequent induction of inflammation.
Excessive cold or heat predispose to rupture of cells with induction of inflammation
Acid, alkaline, or caustic substances have destructive effect on cells and induce inflammation
Bacteria, virus, parasites, or mycotic destroy tissue and induce inflammation; however inflammation due to microorganisms is more serious than that caused by other causes owing to;
1-The destructive local effect
2-The serious general effects of the toxins of many bacteria
Cardinal Signs of Inflammation
It can be seen in non-pigmented skin as a result of;
1-Hyperemia of the inflamed area
2-Extra-vasation of blood
The swelling varies according to the nature of the inflammation (plasma in acute form and fibrous tissue in chronic form), and it is more marked in vascular than in non-vascular structures, and in loose tissues than in hard tissues, however enlargement of inflamed area is due to;
1-Hyperemia and increased blood volume in the affected part
Heat associated with inflammation is readily detected in extremities but it is more difficult to be detected in internal organs due to rapid dissipation of heat to surrounding organs. Generally this increase in the temperature of an inflamed area is due to;
1-Increased blood flow
2-Increased metabolic rate
Abnormal heat can be recognized by;
2-Comparing the temperature of the affected part with that of a corresponding place on the other side of the body or with the normal temperature of the region
The pain varies according to;
1-The severity of the inflammation
2-The degree of nerve supply of the region
3-The tenseness and hardness of the overlying tissue
Pain occurs as a result of;
1-Injury and neuritis to the nerve endings by accumulated metabolic waste products or toxins
2-Stretching and compression of nerve terminals due to accumulation of exudates
V-IMPAIRED FUNCTION (FUNCTION LAESA)
The animal reluctant to move, and specific organ functions (like excretion, secretion, and motility) can’t take place, this phenomena ensues as a result of;
Changes of the Tissue during Inflammation
It varies from cloudy swelling to necrosis
Its benefits include;
1-Bringing more of body defenses (blood cells and antibodies) for destruction of irritating agent
2-Bringing more nutrients and oxygen for repair of damaged tissue
1-Changes in Blood Vessels
Momentary constriction of blood vessels occurs directly after the application of the irritant. This is followed by vasodilatation due to vasodilator nerve impulses and local vaso-dilatory action of substances like histamine (chemical mediators). Finally, an increased vascular permeability occur leading to escape of the blood (plasma, leucocytes, and erythrocytes) through the wall of the vessel to the surrounding tissue.
2-Changes in the Rate of Blood Flow
Temporary acceleration of the rate of blood flow ensues as a result of vasodilatation and this is followed by retardation of the rate of blood flow due to;
1-Increasing the capillary bed
2-Margination of the leucocytes
3-Swelling of the endothelial cells lining the capillaries
5-Stasis of blood flow
3-Changes in the Blood Stream
1-Redistribution of the cellular elements of the blood stream
2-Margination of leucocytes by leukotaxine
4-Exudation of Plasma
Exudation of plasma ensues as a result of;
1-Increased osmotic pressure due to;
a-Accumulated catabolic products
c-Changes in colloids crystalloids
2-Increased capillary permeability due to histamine release
5-Migration of Leukocytes
6-Diapedesis of Erythrocytes
Classification of Inflammation
I-ACCORDING TO CONSTITUENT OF EXUDATES
II-ACCORDING TO DURATION
It has very short course and the animal die soon (few hours) after exposure to the causative agent
It is an inflammation that has rapid onset and short duration, with prominent vascular and cellular changes (mainly neutrophils, eosinophils, and lymphocytes)
It is an inflammation that is caused by mild irritant with less prominent vascular and cellular changes (neutrophils decrease and macrophages increase)
It is an inflammation that occurs within months of exposure to the causative agent and lasts for a long time. The circulatory and cellular changes are difficult to be seen in the area, neutrophils are very few in number, macrophages are numerous, and granuloma usually formed by proliferating fibroblasts and mature fibrocytes.
III-ACCORDING TO FATE OF INFLAMMATION
It is characterized by increased tissue size as a result of increased number of the cells
It is characterized by increased tissue size as a result of increased size of the cells
It is characterized by decreased tissue size
It is characterized by excessive fibrous tissue formation
It is characterized by organization of the exudates with fibrous tissue formation leading to adhesion
VI-ACCORDING TO THE CAUSE
It ensues as a result of trauma, blow, kick, or sprain
It ensues as a result of heat, cold, electricity, or radiation
It ensues as a result of alkali, acid, or caustic
It ensues as a result of bacteria (it has direct effect on affected tissue and indirect effect by circulating toxin), viruses, or parasites
Termination of Inflammation
It means that the inflammation suddenly subsides (as the causative agent is slight or very mild
After the process has been completed the inflammatory exudates is reabsorbed, the damaged tissue is repaired by formation of fibrous tissue, and the affected part apparently resumes its normal condition, although histologically it is not the same as it was before the onset of the injury.
In this case pyogenic organisms produce an abscess or other form of suppuration, and the condition usually ends with resolution
This is often spoken of as a termination of inflammation, when the causative agent is strong enough to cause death of tissue
Usually it results from chronic inflammation with excessive formation of fibrous connective tissue that undergoes maturation and the tissue subsequently resumes hard appearance
Prognosis Of Inflammation
It depends on;
1-Nature of inflammation
2-The affected organ
3-The virulence of the causative organisms
Treatment of Acute Inflammation
I-REMOVAL OF THE CAUSE AND REST
The main treatment of an inflammation is the suppression of its cause and rest of both the animal and the affected part. These simple steps have marked and rapid effect on treatment, as they prevent spreading or dissemination of bacteria and give the tissue the chance for repair. Aside from this, the treatment should be directed towards alleviating the pain and functional disturbance, and restoration of normal function of injured organ.
It helps restoration of normal physiologic function by promotion of healing through assisting normal physiologic processes and affecting vascular supply
1-Cold application, Astringents, and Anodyne
It can be used for treatment of acute or sub-acute non-infectious inflammation, and mild inflammation when tissues are not devitalized. It causes vasoconstriction of blood vessels and prevents exudation, but its prolonged use may cause vasodilation either as a reflex during use or directly after application, so it must be used with pressure bandage and rest.
It can be used alone 24-48 hours post injury (for 20-40 minutes and repeated every hour), or as alternating heat and cold after 24 hours.
Anodyne like iodoform ointment can be used for treatment of painful lesion. It can be used for treatment of injury of muscles, tendons, ligaments, or joints, or for burns in order to;
1-Relieve pain (via induction of some analgesia)
2-Lower tissue metabolism
3-Shorten recovery period
4-Prevent edema and tissue swelling (via vasoconstriction)
A-Running cold water or moist therapy: -
It should be used for an hour at least, and it is contraindicated in presence of open wounds
B-Ice bags: -
It can be used even through bandage, but it shouldn’t be used for tissues that are threatened with death as it may cause vasoconstriction and aggravate the condition
Lead acetate can be used for induction of vasoconstriction
2-Heat Application or Thermotherapy
It can be used for promotion of resorption of noninfectious inflammatory swelling, caused by blood or serum 24-48 hours post injury
It improves circulation and prevents death of injured tissue, but it should be used under control of antibiotic as it predisposes to deeper spread of bacteria and toxin.
Aim of use: -
1-It increases metabolism, number of phagocytes, lymph flow, and oxygen supply.
2-It causes vasodilatation with increased permeability and rising of temperature. This may lead to increased absorption of toxin, and increased swelling after application, so it must be followed by active or passive action either manually or by exercise.
Heat is applied in the form of:-
A-Superficial heat: -
It causes superficial inflammation that doesn't extend far beneath skin
1-Conductive heat (superficial penetration): -
a-Moist heat: -
It should be associated with massage during application, and massage after application using alcohol, liniment, or mild rubefacient to aid massage and to induce erythema, and antiseptic solution can be added in case of septic inflammation
1-Hot water poultice
2-Hot fomentation, turbulator, or whirlpool (induces passive massage)
b-Dry heat: -
1-Hot water bottle
2-Electric heating pad
3-Ultra violet light
2-Radiant heat of deeper penetration (Infra-red light):
It is either luminous or non-luminous (metal coil and has no danger of bulb breakage). It is used for frost bites or pointing of abscess, for 20-40 minutes, repeated every hour, and kept 45 cm far from the animal to avoid burns that have no pain initially but thermal burns appear later on.
B-Deep heat: -
1-Conversive heat: -
Heat ensues as a result of tissue resistance to energy
a-Ultra-short wave diathermy: -
It is ultra-short wave diathermy, shock wave or high frequency electrical energy. Heat penetrates 5 cm deep, and it can be used twice daily. It has direct relationship with water contents of tissue, but metal objects like bone nails can be heated high enough to cause bone necrosis.
b-Sound waves or Ultra-sound: -
It can be used 48-72 post injury (to avoid hematoma and seroma), for 5-10 minutes to produce micro-massage and heat (41˚C) that penetrates 8-12 cm (as deep as bone and may cause demineralization), and it help for function restoring by relief of pain. The head should be kept in motion and contact over the shaved skin using coupling agent (mineral oil). It can be used for treatment of soft tissue injury with no bone affection, even in presence of metal objects, like muscles, tendons, bursa, trauma, nerve damage, or scar of contracted tissues, either alone or associated with corticoid.
1-In presence of bone injury, cancer (to avoid dissemination), or local analgesia
2-Prior to radiotherapy (10 days) and post radiotherapy (up to 2 months) as radiotherapy produces prolonged inflammatory reaction
3-Massage and Compression
It is used for sub-acute or chronic inflammation, combined with liniment to aid massage. Massage promotes resorption of swelling and prevents skin adhesion to the underlying tissues, while compression warms tissue, supports affected area, and reduces swelling.It should be done in direction of venous and lymphatic drainage for 5: 10 minutes but as it has transient effect and should be repeated several times a day.
It induces muscular contraction and relaxation so it can be used for treatment of muscle strain and joint sprain via prevention of adhesion and muscular atrophy, promotion of joint mobilization, and resorption of inflammatory swelling and hematoma.
It strengthens the limb and rehabilitates the horse after injury as it removes swelling during sub-acute or chronic inflammation like puncture wound of the limb, midline incision, or castration. It can be used as hand lead with massage using liniment, or swimming.
Scarification can be used to relieve tension and pain from affected area via release of fluid infiltrated the tissue, but it may cause infection of affected area
It is used for acute inflammation to reduce movement, prevent spread of inflammation, reduce swelling, permit healing, minimize scar formation, and to support damaged structures.
1-Allow healing of bone or tendon
3-Support the limb to prevent contraction of tendons or overstress
1-It shouldn't be used for infectious inflammation unless antibiotic is used, as it tends to spread bacteria and toxins deeper into tissues
2-It shouldn't be left for more than 3 days without changing to avoid skin necrosis and sloughing
3-Strong liniment shouldn’t be used under it to avoid severe blistering
V-POULTICES, CATAPLASMS, OR ANTIPHLOGISTICS
They work through high osmotic tension to draw fluid from tissue toward the surface. It can be used for infectious and noninfectious inflammatory conditions even over puncture wound. It can be used under plastic sheet and bandage. It can be left in position for 12-48 hours.
1-Unna’s paste (Zinc oxide 15 gm, gelatine 15 gm, glycerine 35 gm, and water 35 ml)
2-Magnesium sulfate paste
3-Boric acid paste
4-Kaolin poultice (Kaolin, glycerine, aconite, and water)
5-Anti-phlogestics like icthyol
They are drugs used for acute noninfectious inflammatory conditions to relief pain and swelling, and to reduce fibrosis
1-Relief of post-surgical pain and swelling, in combination with antibiotics as they lower immunity
2-Relief of pain due to tenosynovitis, splint, or bucked shin, by local injection
3-Relief of pain and swelling, and lower fibrosis, when injected parenterally, in combination with cast for treatment of tendosynovitis
4-Relief of pain during acute arthritis by intra articular injection, in combination with hyaluronic acid, and must be preceded by radiographs to ensure absence of chip fracture. This must be performed under aseptic condition and with compression. It acts on synovial membrane, allowing recovery of cellular function, reduction of synovial volume, and increasing its viscosity.
Side effects: -
1-Lowering immunity and predisposes to infection, so it must be used with antibiotics
2-Destruction of articular cartilage
3-It masks signs of inflammation
4-It causes rapid relief of pain leading to early forcing of the animal to work and destruction of affected joint, so it should be associated with rest
1-It shouldn't be during degenerative arthritis or reparable fracture of the joint
2-Injection of long acting corticoid (for joint only) into soft tissue as it causes tissue calcification
4-It shouldn't be used in adjunction with counter irritation
5-It shouldn't be used with chip fracture of joint as it masks signs of inflammation, relieves pain, and causes more destruction of the joint by demineralization of bone fragment and erosion of the cartilage, and increases incidence of post-surgical infection.
a-Acetyl salicylic acid (aspirin)
Treatment Of Chronic Inflammation
I-RUBEFACIENTS & COUNTER IRRITANTS
It is used to change sub-acute or chronic inflammatory process to a more acute form in the hope that resolution will occur when the acute inflammation heals. This occurs via induction of local hyperemia, increasing blood supply, with subsequent attraction of more oxygen, nutrition, and WBCs for repair of inflamed area, and resorption of exudates.
They increase circulation leading to redness and mild heat, and it should be repeated once or twice daily as it has temporary relief. It can be used to relief pain during muscular or joint soreness. It has many terms like iodine ointment, icthyol, liniments, tightener, brace, and sweat, with very little difference among them.
Iodine ointment 5-10 % can be used over affected area and the remaining vaseline should be removed every new application to prevent isolation of the newly applied ointment from coming in contact with skin. Application should be associated with massage in one direction (the heart direction usually).
Liniments contain one or more of essential (volatile) oils, their use on limbs can produce considerable edema and skin soreness, their blistering effect increases when applied under bandage, and if the reaction is severe or neglected scars and denuded areas can result
i-Camphor and cottonseed oil
ii-Camphor and soap liniment
It is any combination of drugs used to aid removal of edema or synovia of a joint capsule or tendon sheath, so that the tendons are more palpable. The effect is related to massage and bandage rather than being related to the drug itself. It shouldn’t be applied over skin soreness, and should be applied daily and covered with cotton and bandage for 5 days.
Tincture of belladonna 4oz, tannic acid powder 2oz, menthol crystals 2oz, camphor crystals 1oz, and alcohol q.s.1qt.
It is drug used to induce accumulation of moister over skin, and most products that have alcohol can induce such effect. It must be used under plastic wrapping, oiled silk, or waxed paper
ii-Alcohol and glycerin
It is a mixture of drugs that used routinely following workouts (at night), with massage and compression bandage, to prevent filling of joint capsule or tendon sheath
II-BLISTERS or VESICANTS
It is used for subacute or chronic inflammation to produce blistering and inflammation down the subcutaneous tissue. Generally it is ineffective painful method, especially for bone conditions like exostosis
1-Red iodide (Bin-iodide) of mercury & Cantharides (Spanish fly)
1-Chronic inflammation of joints
2-Chronic bone conditions
3-Tendonitis, synovitis, or tendosynovitis
4-Pointing of abscess
General roles of application: -
2-Rubbing for 5 minutes
3-Should be removed after 8-24 hours.
4-Application of petroleum jelly at the periphery
1-Cross tying to prevent licking
2-Don’t use it for young animals.
3-Shouldn't be used on medial aspect of the thigh
4-Iodide interferes with interpretation of radiographs.
1-Acute inflammatory conditions
3-Flexor surfaces except fetlock.
4-Near mucous membranes
6-Injection of corticoid (up to 30 days)
Seton in the form of gauze impregnated in turpentine oil and inserted subcutaneously from one opening to a ventral one, and it should be kept in situ for 14 days
IV-THERAPEUTICN CAUTERY or FIRING
It changes sub-acute or chronic inflammation into acute form in hope that it will undergo resolution.
1-Soft tissue damage (around joints, tendons, and ligaments)
2-Carpitis (popped knees) especially if there is no periosteal new bone growth
4-Tendonitis and tendosynovitis
5-Osselets, with no periosteal new bone growth
6-Sesamoiditis, bone spavin, or splints
1-Near open wound, area of dermatitis, or infection
4-Flexor surface of joint
5-Young or emaciated animals
6-Active new bone growths
7-When corticoid has been used (up to 30 days)
It can be applied either as block or diagonal pattern and it can be used as superficial (no skin penetration) or deep point firing (the skin is penetrated)
2-Scrubbing with soap and antiseptic
3-Induction of local analgesia
1-Holes shouldn’t be closer than 1 cm
2-Iron should be heated to cherry red
3-Don’t fire for too long time to avoid necrosis and sloughing
4-Don’t apply excessive pressure to avoid penetration of synovial structures or bone
5-Avoid sudden movements of the horse
6-Avoid penetration of blood vessels
It can be used as transverse, oblique, or tree manner and it shouldn't penetrate skin. It can be used over volar surface of tendons or the long axis of stifle joint and generally the edge of the instrument shouldn’t be more than 3 mm wide. It is not recommended and doesn’t cause any more irritation than blistering
3-Needle point firing
It penetrates deep and reaches bone or ligament but it is not recommended to be used near joint or tendon to avoid infection of these structures
Aftercare of firing: -
1-Blistering for 21 days by 2 parts Tr. Iodine 7%, 1 part glycerine, and 1 part liquid phenol. It acts as germicidal and local anesthetic and it produces prolonged irritation.
2-Rest for 6 months
1-Sloughing of skin
2-Wound infection and septicemia
4-Suppurative arthritis and synovitis