Coccidiosis is highly infectious and quite a common illness that infects the intestines of birds. It usually exists to some degree in all pigeons, but most adult birds produce sufficient immunity to the disease to continue to be healthy.
Signs of a Coccidiosis infection in pigeons include:
Young pigeons are most typically infected, or birds that have been subjected to severe stress (i.e. racing, exhibiting, lack of food and water, or relocation). Adult birds may become contaminated from consuming unclean water or from coming into contact with moist droppings.
There are a wide range of treatments specially formulated to treat coccidiosis in racing pigeons. Water-soluble treatments, such as Harkers Coxoid, are generally easier to administer.
That said, if you’re just treating a few birds a tablet treatment may be more effective.
In addition to administering preventatives such as a 3 in 1 (which also covers canker and internal parasites such as worms).
You should try to keep the loft dry and sanitary.
Do not allow feed to come into contact with droppings, and disinfect drinkers often and race baskets weekly. Additionally, whenever possible don’t let the birds drink from gutters or mud puddles.
Another thing to be mindful of is when bringing new birds into the loft they should ideally be isolated at first, since they may facilitate the spread of coccidiosis to your healthy birds. Pigeons returning from a race need to be provided with a preventative remedy shortly following their return, especially if out overnight.