Coccidiosis is a disease caused by the coccidial protozoan organism, an internal parasite called Eimeria. These live inside the cells that line the birds intestine.
As they reproduce, they cause bleeding and swelling in the intestines. Birds lose a lot of liquid through diarrhoea and cannot absorb nutrients from their food and will soon die if they are left untreated. Coccidiosis normally only infects young birds. Older birds will build up an immunity over time. There are a number of different species of Coccidiosis parasite, some cause a higher mortality rate than others. There are five that can cause death in Chickens, 3 in Ducks, 3 in Geese, 5 in Turkeys, 3 in Pheasants.
Species Affected: Chickens, Turkeys (mainly Poults), Ducks, Geese (mainly Goslings), Pheasants. Each Eimeria species is specific to its host (so chickens can't infect Turkeys for example).
Other Names: Cocci
Symptoms: Bloody Diarrhoea, ranging from clotted blood to slightly tinged faeces and mucus. Poor feed conversion, loss of weight, death.
Area affected: Intestines.
Causes: Coccidial protozoan organism, an internal parasite called Eimeria.
Transmission: Coccidia eggs (called oocysts) eaten by a bird hatches inside the intestine and multiplies (within 7 days) laying thousands more eggs. Once these eggs pass out via the infected faeces, they require 2 days to mature (ideally around 25 to 30°C in moist conditions) before they are ready to infect another bird.
Diagnosis: Symptoms above.
Prevention: Keeping chicks and growers clean and out of damp litter so they cannot peck at droppings is the most important preventative measure. Good biosecurity: keeping age groups separate, keeping younger birds off ground that has been used by older birds, cleaning footware if visiting younger birds after older birds. Vaccination at day old where practical. The only DEFRA approved disinfectant that kills the 'Oocysts' (Coccidia Eggs) is "Bi-OO-Cyst".
Treatment: If there is a consistent problem, there is a vaccination available for chickens (called Paracox). This can be administered in water, it contains all 7 species of coccidia that chickens can get. It is normally only available in vials suitable to treat 1000 birds that has a shelf life of 4 weeks. It should be used on day old chicks via drinking water or pipette / dropper. Chick crumbs can contain anti-coccidial drugs (sometimes called ACS) although recently, many feed manufacturers have been reducing the amount of ACS they put in their feeds and there is growing concern that some of these drugs are not as effective as they used to be.
For birds that are suffering with Coccidiosis, we are aware that in the absence of licensed alternatives, veterinarians do sometimes prescribe drugs such as Harkers Coxoid under the 'cascade' to treat Coccidiosis in poultry. However, it is only a veterinarian who can advise on such use and we would be in breach of the veterinary medicines regulations and NOAH code of practice by supporting, or encouraging the use of a product on a non-target species.
Coxoid is administered in water and has proven to be very effective. For it to be effective, it is important to do this quickly at the first signs of Coccidiosis infection. If using Coxoid, chicks need to have unmedicated chick crumb as the ACS can work against the Coxoid and make it ineffective
Risk to Human Health: None known.