Surgery of Gangrene in animals
Surgery of Gangrene in animals is surgical removal as it is a necrosed part.
Gangrene is necrosis and subsequent decay of body tissues caused by infection or thrombosis or lack of blood flow.
Gangrene is usually the result of critically insufficient blood supply sometimes caused by injury and subsequent contamination with bacteria. This condition is most common in the extremities.
Etiology of Gangrene
The main factors in gangrene are loss of blood supply, and later invasion of the part by micro-organisms.
Gangrene may be caused by-
Direct damage to tissues
Mechanical compression or interference with blood and nerve supply to a part of the body or an organ while lying on a hard floor. Example: bed-sores; sit-fast.
Physical agents like application of heat and cold. Example: burns, frost-bite.
Action of acids, alkali and other chemicals producing dry gangrene and moist gangrene.
Impaction of intestine in the hernial ring and infestation with pathogenic microbes especially with anaerobic infection.
Indirect changes in tissues
Indirect changes in tissues due to cardiac, venous, arterial or nervous affections like-
Ergot intoxication, which causes spasmodic narrowing of arterioles and leads to dry gangrene of extremities. It is commonly seen in feet of cattle.
Diabetic gangrene narrows arteries and sugar in tissues, favours bacterial growth.
Senile gangrene i.e. arteriosclerosis in old age, which narrows lumen of blood vessels.
Common sites of affection of gangrene
Extremities like legs, ears, tail, wattle and combs. It is mostly due to freezing or ergot poisoning.
Mammary gland: Staphylococcal mastitis produces necrosis due to toxins or thrombosis of mammary vessels.
Involvement of lung due to wrong drenching of medicines, improper passage of stomach tube or severe lung infection.
Intestines in equines are commonly involved either with infarction due to verminous thrombosis of anterior mesenteric artery; or due to acute, local passive hyperaemia produced by intestinal torsion, volvulus or intussusceptions.
Classification of Gangrene
| Type | Etiology | Characteristic signs |
| Wet gangrene, or moist gangrene | Sudden interruption of blood flow such as due to burns, freezing, injury or blood clot. Wet gangrene spreads very quickly and can be fatal. | 1. Affected tissue may appear badly bruised, swollen or blistered. 2. May also become infected. 3. No clear line between healthy and affected tissue. |
| Dry gangrene | Insufficient blood flow through the arteries such as due to atherosclerosis or blood clots. It usually doesn’t involve bacterial infection. | 1. Affected tissue becomes shriveled, dry and blackish or greenish colour. 2. cold to touch |
| Gas gangrene | Infection with certain types of bacteria, such as clostridium. It typically occurs at the site of a recent injury or surgery. The bacteria rapidly destroy muscle and surrounding tissue. | 1. Swelling around skin due to exudates and gas formation. 2. Skin initially looks pale and then turns dark red or purple in color. 3. Offensive odour of exudates. |
Diagnosis of Gangrene
Diagnosis of gangrene will be based on a combination of-
- History (recent trauma, surgery, cancer, or chronic disease)
- Physical examination
- Results of blood and other laboratory tests (presence and extent of infection).
Treatment of Gangrene
Prevention of cause and extension of gangrene is the only option.
Debridement: Removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue.
Application of warm antiseptic fomentations to relieve pain.
Surgical excision or amputation of a limb or organ.
Antibiotics alone are not effective because they do not penetrate ischemic muscles sufficiently. However, penicillin is given as an adjuvant treatment to surgery.
In addition to surgery and antibiotics, hyperbaric oxygen therapy (HBOT) is used that inhibit the growth and kill the anaerobic organisms.