How is animal fat rancidity poisoning in mink diagnosed and treated?

Animal fat rancidity poisoning

Animal fats, especially fish fats, contain many unsaturated fatty acids and are prone to oxidative rancidity and yellowing, releasing a rancid odor and decomposing to produce harmful substances such as fish oil toxins, neurotoxins and paralytic toxins, undergoing slow oxidation at low temperatures. Therefore, fish feed stored frozen for a relatively long time is the main cause of acute and chronic yellow fat disease in mink, especially high-fat fish such as saury and oil fish, which are even more seriously affected. In addition, failure to pay attention to vitamin E supplementation or insufficient supplementation in the feed can easily cause this disease.

Clinical symptoms:

This disease tends to occur in mink herds fed mainly on frozen stored fish and meat feed. Generally, young mink with a strong appetite or good development are the first to be affected and die; acute cases collapse and die suddenly. In large groups, mink show loss of appetite, listlessness, unwillingness to move, and diarrhea. In severe cases, black tarry diarrhea resembling coal tar appears in the later stage, or hindquarters paralysis and abdominal warmth on urination occur, and death often occurs in a comatose state.

On palpation, the fat on both sides of the groin feels hard like lard or cord-like. Chronically affected mink often show reduced appetite, emaciation and unwillingness to move. Adult mink are prone to this condition, and it is easily confused with Aleutian disease.

Treatment:

Feeding of deteriorated and moldy animal feed should be stopped immediately, and vitamin E should be added. For large groups, key individual examinations should be carried out, palpating the changes in the groin fat; any mink found with fat masses or diarrhea should be included as treatment subjects.

Affected mink are given intramuscular injections of 0.5-1 ml of vitamin E injection, 0.5 ml of compound vitamin B injection, 200,000 units of penicillin, and 1.25 mg of dexamethasone once daily for 3-5 consecutive days. For emaciated affected mink, 5-10 ml of 25% glucose can be injected subcutaneously.

Prevention:

Attention should be paid to feed quality and management of cold storage should be strengthened. Fish and meat feed found to have yellowed or rancid fat should be dealt with promptly or discarded. In addition, for mink herds fed mainly on fish feed, attention must be paid to vitamin E supplementation.