How can I prevent my pheasants from being infected with coccidiosis? Daltons Game Consultancy provides expert advice...
Q: Every year I rear about 10,000 pheasants. Last year they had coccidiosis. How can I prevent it?
RITA ALVES of Daltons Game Consultancy replies: Coccidiosis is caused by a parasite of the intestinal tract called Eimeria spp, usually causing diarrhoea, lack of appetite, weight loss and sometimes death in pheasants and partridges. Coccidia are host-specific, i.e. they only affect one species of birds. This means the coccidia that affect pheasants will not affect partridges and vice-versa. They are also site-specific, meaning each species of coccidia will only colonise a certain part of the intestine of the bird. In pheasants, it is usually seen in the rearing field around 3-5 weeks of age and in older birds after they are transferred to the release pens. Once exposed to coccidia, birds will develop immunity to the disease.
Birds will get infected when they ingest oocysts (the latest stage of the parasite cycle) which have been passed in the faecal droppings of other birds, usually via contaminated drinking water or feed. Moisture and warm temperatures are the ideal conditions for the ‘sporulation’ of the oocysts on the ground. Only oocysts which have been ‘sporulated’ are infective. Once the bird ingests the ‘active’ oocyst, the coccidia go through a complex seven-day lifecycle of several stages in the intestinal cells causing damage and disease. Depending on the age, birds can usually cope with small levels of infection, usually controlled by the coccidiostast in feed. But when birds are stressed (e.g. during bitting) or the environment is highly contaminated, the challenge is too high and birds get ill.
The best way to avoid birds getting infected is to avoid high stock densities, to keep the bedding dry and to move drinkers and feeders daily to avoid hot areas (areas highly contaminated with faecal droppings). Oocysts are very tough and can survive in the environment for a year, so you can also use a disinfectant specific for coccidia to clean the sheds and equipment before receiving the day-olds.
If you rear more than one batch, always work from the younger batches to the older ones or, if possible, try having only one age group.
You should discuss with your vet a health plan, where you can monitor the levels of oocysts in the faecal droppings and/or use an anticoccidial drug in the drinking water following stressful periods (e.g. bitting). It is important to remember that it is almost impossible to prevent contact with oocysts and that we should allow birds to develop immunity before they are released without them getting ill.