Introduction
Infection of chickens with the protozoan parasite Eimeria praecox is spread in exactly the same as that with E. mitis but is practically non-pathogenic.
Signs
- Normally asymptomatic but may cause reduced feed efficiency and reduced weight gain, and predispose to other intestinal conditions.
Post-mortem lesions
- Minimal, but usually excess liquid and mucus in the duodenal loop.
- Severe infection can cause dehydration through excessive fluid loss.
- The cells of the sides of the villi (not tips) are usually parasitised.
Diagnosis
Identification of characteristic slightly ovoid oocysts in the duodenum in the absence of E. acervulina lesions. It has a very short pre-patent period (c. 80 hours).
Treatment
Not usually treated but susceptible to the products used for other forms of intestinal coccidiosis.
Prevention
Normally controlled by anticoccidials in feed. Not usually included in vaccines.
Coccidiosis, Ileorectal, E brunetti
Introduction
A relatively rare form of coccidiosis affecting chickens worldwide caused by Eimeria brunetti. Of moderate to high pathogenicity, it is found in the terminal ileum, caecum and rectum. Morbidity and mortality are variable.
Signs
- Depression.
- Ruffled feathers.
- Closed eyes.
- Inappetance.
- Poor production.
- Diarrhoea, blood in faeces.
Post-mortem lesions
- Petechiae and thickening of the distal third or more of intestine, extending into caecal tonsils.
- Severe necrotising enteritis.
- Oocysts in caecum and rectum.
Diagnosis
Signs, lesions, microscopic examination of scrapings. Differentiate from ulcerative enteritis, caecal coccidiosis.
Treatment
Toltrazuril, Sulphonamides, Amprolium, Vitamins A and K in feed or water.
Prevention
Coccidiostats in feed, vaccination by controlled exposure, hygiene. This species is not usually included in vaccines for broilers. There is good immunity to the same parasite in recovered birds.