This is primarily an infectious disease of ruminants that results due to absorption of certain bacterial toxin which is being formed in the intestine.
Enterotoxaemia has been reported from cattle, sheep, lambs, foals and pigs from countries like Australia, UK, Japan. It has also been reported from New Zealand and North America.
Enterotoxaemia is an important common disease of sheep and goat population caused by Clostridium perfringens in the intestine and liberation of beta and epsolom toxins. The disease is considered to be the most important killer disease in goats and has been recorded from various parts of India. A recent outbreak has been reported in Tamil Nadu in goat. The disease has been experimentally produced in goats. Characterization of Clostridium perfringens has been made through DNA-DNA hybridization. DNA probes were derived from multicopy recombinant plasmids carrying searched genes. All the isolates showed characteristic biochemical reactions. 11 isolates hybridized with the alpha-toxin, mu-toxin and sialidase gene probes upon DNA-DNA hybridization with 13 Cl. perfringens gene probes. Cl. perfringens type A used to produce a transient, diarrhoea and it subsides within 12 hours. On the other hand type-D produces typical enterotoxaemia and death within 36 hours following experimental transmission.
Toxoids are used for protection since bacterin vaccine is not satisfactory. Single vaccine with beta and alpha toxoids may produce satisfactory level of immunity in buffalo calf, calf, goat and sheep.
Aetiology
Enterotoxaemia is caused by Clostridium perfringens that produces toxins starting from A to F of which Clostridium type A, B, C, D, E are important.
Clostridium perfringens Type-A
The exact role of type-A in relation to disease in cattle, calves and lambs is not clear. It produces toxin. Enterotoxemic jaundice is seen in sheep and cattle. This is characterized by intense icterus, haemoglobinuria and hemoglobinemia. The affected animal will show respiratory distress and bloody foam from mouth and nostrils. Pulmonary emphysema may occur due to type A infection.
Clostridium perfringens Type-B
Synonym: Lamb dysentery
The organism produces a disease known as lamb dysentery. Besides lamb, the disease has been reported in colts and calves. Organism produces alpha, beta and gamma toxin. The beta toxin produces enteritis and gamma toxin affect the neural tissues. The disease is characterized by severe dysentery, abdominal pain, spasms and aimless wandering. Per-acute case will lead to sudden death without showing any clinical manifestation.
Small necrotic areas surrounded by zone of haemorrhages are noted in the intestinal mucosa. There is enlargement of mesenteric lymph nodes. Liver is enlarged and friable.
Diagnosis can be made based on changes in the intestinal mucosa and demonstration of toxin by mouse inoculation test.
Oral and systemic antibiotics may be tried but the treatment very often does not yield satisfactory response. Antitoxin if available may be given soon after birth. Immunization of ewe prior ro lambing may prevent lamb dysentery.
Clostridium perfringens Type-C
Synonym: Struck
It affects the sheep, goat and cattle. It produces haemorrhagic enterotoxaemia which is an acute disease of young calves. It produces both alpha and beta toxin. Excess feeding of milk causing intestinal stasis favours the multiplication of the organisms and thereby production of toxin. The clinical signs include abdominal pain, weakness, depression, failure to nurse and haemorrhagic diarrhoea.
The lesions are found in the small intestine particularly in the jejunum and ileum characterized by haemorrhagic changes. There is also necrotic and ulcerative changes. Small haemorrhagic lesions may be noted in the epicardium, thymus and diaphragm.
Diagnosis is made based on history, sudden death, haemorrhagic enteritis, isolation of toxin, presence of gram positive bacilli in the intestinal smear and demonstration of toxin in the intestinal content.
Oral antibiotics (tetracycline, chlortetracycline, penicillin) may be used.
For control, immunization of calves with antitoxin soon after birth is suggested. Two injections of toxoids are necessary at one month apart. Cow should be immunized one to three month prior to parturition. Sheep may be vaccinated with ETV-CD (BAIF) vaccine.
Clostridium perfringens Type-D
Synonym: Pulpy kidney disease
It is primarily a disease of sheep but cattle and goats are occasionally affected. It produces alpha toxin. The young sheep and calves are affected.
There is diffuse reddening of abomasal mucosa, sub-endocardial and myocardial haemorrhage. The CNS may be affected. For this, animal may become blind. Sheep may show the signs of glycosuria. Straw coloured fluid is found in the peritoneal, pleural and pericardial sac.
In sheep, the disease is known as pulpy kidney disease. Affected lamb may jump in the air, fall in the ground go into convulsion and die within few minutes.
The sheep hat die suddenly may not show any post mortem lesions.
Haemorrhagic lesions are seen in the peritoneum, epicardium, endocardium, diaphragm, abomasum and duodenum. There is softening of kidney. Kidney changes develop in 3 to 4 hours following death.
Formalised anaculture is used for vaccination of lambs and ewes. Broad spectrum antibiotics like Chlortetracycline may be used for treatment. ETV-D Clostridium welchi type-D vaccine (BAIF) can be used against sheep.
Clostridium perfringens Type-E
Clostridium perfringens Type-E produces alpha and beta toxin. There is fatal infection leading to death. There is haemorrhagic changes in the intestine.
Clostridium perfringens Type-F
The organism produces potent toxin and caused diarrhoea in calves and lamb. It is not certainly known to be the causative agent of any fatal diseases of animals.
