Yellow Lamb Disease (Enterotoxemia Type A)

Yellow Lamb Disease (Enterotoxemia Type A) is a sporadic disease affecting all group of animals.

Clostridium perfringens Type A is a major cause for abomasal inflammation, which may result in abdominal distension, abomasal ulcers in young calves. Varying degrees of diarrhoea, and occasionally sudden onset of weakness and coma.

Yellow Lamb Disease (Enterotoxemia Type A) affects calve 2 weeks to 4 weeks old. Haemolytic Enterotoxemia in foals and in goats developed by alpha toxin, which possess phospholipase C and sphingomyelinase acitivity.

Etiology

• C. perfringens isolates are categorized in to type A-E as based on their ability to produce alpha, beta, epsilon, and Iota toxins.
• These toxins are important to exert their effect in developing pathogenesis.
• It is caused by Clostridum perfringens Type – A alpha toxin.
• Clostridium perfringen is a gram-positive, spore-forming, anaerobic bacteria.

Epidemiology

Prevalence of infection

• C. perfringens type A has been suggested as a cause of jejunal hemorrhage syndrome in beef and dairy cattle and calves in most of the temperate countries predominantly in Canada, Belgium, in the western United States including in India.

Predisposing factors

• It is also occasionally associated with wound contamination and gas gangrene.

Sources of infection

• Organisms found in many environments, including soil, water, poorly preserved feeds, contaminated or improperly thawed colostrum or milk, Calf sheds and the normal bovine intestinal tract.

Transmission

• Contact with infected group of animals.
• Ingestion of contaminated feed and water materials with organism.
• Inhalation of spores.

Host affected

• All animals such as cattle, sheep and goats, horses, pigs are affected.
• Young one of the above species are highly susceptible to the disease.

Pathogenesis

• C. perfringens type- A produce alpha toxin.
• It possess phospholipase C and sphingomyelinase activity and consequently, haemolytic action.
• The presence of Beta 2 toxin in these strains may contribute to the pathogenecity leading to high temperature, jaundiced mucous membrane, haemoglobinuria.
• Affected animals die in 12 hours.
• Cattle develops jejunal haemorrhagic syndrome.

Clinical Signs

Horse

• Acute profuse diarrhoea with high mortality in adult.
• Affected animal die following strenuous exercises.

Pigs

• Enteritis, watery yellow diarrhoea, in piglets less than 5 days of age.
• High morbidity and low fatality.

Cattle, Sheep and Goats

• Haemorrhagic enteritis in calf and adult cattle.
• Haemolytic disease in goats.
• An acute increase in body temperature, severe depression, pale mucous membrane, jaundice, hamoglobinuria, dyspnoea and severe abdominal pain.
• Affected animals collapse and die in 12 hours.

Necropsy Findings

• Horse- Cecitis and colitis
• Pigs- Mild enterocolitis and villous atrophy.

C. perfringens-Type-A Necropsy Findings:

• Haemorrhagic, necrotizing enteritis, with a abundant fibrin in a week old pig.
• Cattle, sheep and goats: The disease is highly fatal.
• Haemolytic disease and haemorrhagic enterotoxemia.
• Jaundiced mucous membrane, swollen kidney, dark brown in colour and contains infarcts.
• Liver is pale and enlarged.
• Hydropericardium and pulmonary edema.
• Extensive necrosis of the intestine.

Diagnosis

• Isolation of organism from young and adult animals feces with enterocolitis.
• The organism can be isolated from young one even when they are 3 days old.
• Identification of Beta 2 toxin in feces (enterotoxin gene).
• Beta toxin detection in gut contents.
• It may cause protease degradation.
• Cytotoxic assays and immunoassays.
• The organism present in the intestine of normal calves.
• Culture of the organism from the calf is not sufficient to confirm a diagnosis of disease due to C. perfringens. So culture results should be confirmed with clinical signs, lesions in the tissues, and, in some cases, toxin identification, to obtain a true diagnosis.
• Tissue samples from calves should be collected soon after death and preserved.

Differential diagnosis

• Chronic Copper Poisoning

Treatment

• In subacute and chronic cases, antitoxin along with Tetracycline orally at the rate of 11 to 22 mg/kg bodyweight will usually effective.
• Supha group of drugs as injection or tablets may be given. Sometimes sulpha drugs in combination with trimethoprim can be tried.

Prevention

• Type A antiserum is very effective in preventing disease in calves.
• Formalised vaccine has some effects in controlling.

Control

Control of enterotoxemia due to C. perfringens infection focuses on three areas:

1. Minimize exposure
2. Enhance immunity in the young calf
3. Managing feeding practices to prevent the proliferation of C. perfringens in the gut