Coccidiosis in Poultry

Coccidiosis in Poultry

Caused by protozoa of the phylum Apicomplexa, family Eimeriidae. Most species belong to the genus Eimeria and infect various sites in the intestine.
The infectious process is rapid (4–7 days) and is characterized by parasite replication in host cells with extensive damage to the intestinal mucosa. Poultry coccidia are generally host-specific, and the different species parasitize specific parts of the intestine.
Coccidia are almost universally present in poultry-raising operations, but clinical disease occurs only after ingestion of relatively large numbers of sporulated oocysts by susceptible birds.
Both clinically infected and recovered birds shed oocysts in their droppings, which contaminate feed, dust, water, litter, and soil. Oocysts may be transmitted by mechanical carriers (eg, equipment, clothing, insects, farm workers, and other animals).
Fresh oocysts are not infective until they sporulate; under optimal conditions (70°–90°F [21°–32°C] with adequate moisture and oxygen), this requires 1–2 days. The prepatent period is 4–7 days. Sporulated oocysts may survive for long periods, depending on environmental factors. Pathogenicity is influenced by host genetics, nutritional factors, concurrent diseases, age of the host, and species of the coccidium.
Eimeria necatrix and E. tenella are the most pathogenic in chickens, because schizogony occurs in the lamina propria and crypts of Lieberkühn of the small intestine and ceca, respectively, and causes extensive hemorrhage. Most species develop in epithelial cells lining the villi. Signs of coccidiosis range from decreased growth rate to a high percentage of visibly sick birds, severe diarrhea, and high mortality. Feed and water consumption are depressed. Weight loss, development of culls, decreased egg production, and increased mortality may accompany. When you notice these signs, call your VET immediately. Only a trained Veterinarian can help avoid the massive loss of your birds to Coccidiosis.