Necrotic enteritis occurs worldwide in broilers, broiler breeders and commercial layer pullets, aged between 3-6 weeks. It is caused by clostridium perfringens types A or C. The organism is transmitted by soil, dust, litter and faeces. Can be induced by choice of raw materials in feed and/or coccidiosis. Clostridium perfringens can become especially prevalent in the small intestine when no antibacterial growth promoters are used.
- Causes of Necrotic enteritis >
- Effects of Necrotic enteritis >
- Diagnosis of Necrotic enteritis >
- Treatment & Control of Necrotic enteritis >
Causes of Necrotic enteritis
All types of chickens from two weeks onwards are susceptible to this acute to chronic disease. The agent involved in the aetiology of the disease is Clostridium perfringens which produces types A and C alpha toxin and type C beta toxin. It is also called creepers because chickens are sometimes ataxic (can’t move).
Mode of transmission
Soil, dust, litter and faeces spread the organism.
Special note
It may cause malabsorption syndrome leading to vitamin or mineral deficiency.
Effects of Necrotic enteritis
Ataxia, intoxication, diarrhoea, depression, ruffled feathers and reluctance to move may be seen. In acute cases death can occur within hours of the disease onset.
Postmortem lesions
Dehydration (darkened skin), emaciation (no breast muscle), congested liver, cooked (ruffled up) intestinal mucosa – primarily of the jejunum and ileum can be seen. Intestines are often distended and filled with gas. There is water in the crop.
In acute cases enteritis occurs with just a grey layer of necrotic material on the mucosa.
Diagnosis of Necrotic enteritis
Diagnosis is based on the gross lesions (ruffled intestinal mucosa), clinical signs and bacterial isolation on blood agar plate. Colonies are surrounded by an inner zone of complete haemolysis and an outer zone of discolouration and incomplete haemolysis. It simulates coccidiosis and ulcerative enteritis.
Treatment & Control of Necrotic enteritis
Prevention
Bacitracin 50 g/ton given continuously in the feed, improved sanitation, lincomycin in feed or water. Rearing birds on wire will prevent the disease.
Treatment
Narrow spectrum antibiotics like Penicillin V (Phenoxymethylpenicillin, see the EMEA_report) or tylosin are recommended as first choice.
Bacitracin (200 g/T) in the feed and vitamins and minerals in the water to reduce the disease. Lincomycin, oxytetracycline, amoxicillin and tylosin can also be used to treat the disease.
Note
Bacitracin is now banned in most countries.
