Struck (Enterotoxemia Type C)

Struck (Enterotoxemia Type C) is a sporadic disease occurs in orphan lambs especially reared on milk replacer.

Struck (Enterotoxemia Type C) is the one of the more commonly encountered types of C. perfringens. It is virulent in calves less than 10 days old.

The disease is characterised by bloody diarrhoea but calves even die before this stage.

Etiology

• C. perfringens isolates are categorised 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 – C produces beta and alpha toxin.
• Clostridium perfringen is a Gram-positive, spore-forming, anaerobic bacteria.

Epidemiology

Prevalence of infection

• Prevalent in cold weather.
• Lamb dysentery reaches 20-30%
• In an outbreak disease initially affects 1-4 days old lambs and the clinical course is very short.
• During the lambing period disease incidence increase.
• The cases fatality rate approaches 100%

Predisposing factors

• Gross contamination.
• In lambs, goats due to close stocking in shed.

Sources of infection

• Poor quality feed facilitate infection.
• Feeding of milk in excess.

Transmission

• Ingestion of infected feed and water.
• Close contact with infected animals.

Host Affected

• Upto 2-3 weeks age groups of lambs and calves are affected.
• Sporadic disease occurs in orphan lambs reared on milk replacer.
• Piglets up to 7 days are most commonly affected.
• Foals and calves  are susceptible for type C

Necrotic enteritis of pigs: Important disease in piglets, particularly in intensive pig units. Organism is recoverable from the skin of sows and faces.

Pathogenesis

• Organism occurs as normal intestinal flora or any dietary changes significantly causes pathogenesis.
• Poor quality of feed facilitates abomasal and small intestinal multiplication of organism with resulting mucosal necrosis.
• Fluid accumulation in peritoneum and thoracic cavity and leading to toxaemia, enteric lesions, dysentery, diarrhoea, often absent.
• Beta toxin affects central nervous system.
• Organism proliferates and attaches to the epithelial cells of the intestinal villi but toxin production and mucosal damage precede the attachment.
• Alpha toxin: It is a lethal toxin, produced in varying amounts by isolates. It is a phospholipase which hydrolysis the membrane phospholipids in RBC, platelets, leucocytes and endothelial cells, results in cell lysis or often develops cytotoxicity.
• Beta toxin: It causes increased vascular permeability and may facilitate the uptake of toxins from intestine. It is a necrotising toxin, initially produces damage to microvilli, degeneration of mitochondria with external distinction and desquamation of the intestinal epithelial cells. Which also develops haemorrhagic enteritis and ulceration of the intestinal mucous membrane. Beta toxin is highly sensitive to inactivation by trypsin which is a component of normal pancreatic proteases.
• Colostrum contains trypsin which inhibits organism in affected young animals. In the absence of trypsin the organism multiply within the intestine and colonisation of organism in the intestine of young animals.

Clinical Signs

Haemorrhagic enteritis, ulceration of intestinal mucosa , diarrhoea, dysentery in young sheep, lambs, goats, calves, pigs, foals along with beta 2 toxin.

High fatality rate, rapid course, haemorrhagic diarrhoea, abdominal pain, and toxaemia.

Diagnosis

• Frequently the organism is isolated from systemic faeces of new born lambs and kids with haemorrhagic enteritis.
• Identification of organism
• Sample collection: 20-30 ml frozen intestinal contents. Air dried smears of mucosal surface from several levels of small intestine, ileum, jejunum, segments of several organs.
• Demonstration of toxin.

Differential Diagnosis

• Rota viral enteritis
• Coronal viral enteritis
• Parvo viral enteritis
• Other enterotoxemic infection (Type A, Type B)

Treatment

• Fluid therapy and supportive treatment.
• Hyper immune serum is a specific therapy.
• Oral and parenteral administration of penicillin prevent further proliferation of organism.
• In the subacute and chronic case, antitoxin along with Tetracycline orally at the rate of 11 to 22 mg/kg  body weight 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

• Prophylactic vaccine

Control

• Fluid therapy
• Administration of hyper immune serum.
• Oral or parenteral administration of Penicillin to prevent further proliferation of organism.