Coccidia belong to a group of microscopic parasites called protozoans. These organisms primarily inhabit the small intestine of affected dogs and cats. The disease caused by coccidia (coccidiosis) is rarely severe, yet the resulting diarrhea it causes can rapidly dehydrate a young puppy or kitten.
Overcrowding and poor sanitation greatly contribute to the spread of these organisms within a group. Eggs passed in fecal material can be directly ingested by another pet, leading to the development and maturation of the organisms within the gut of their new hosts.
If coccidia are ingested by animals other than their normal host (e.g., if the feline Toxoplasma coccidia is ingested by a dog), tissue migration might occur, similar to that seen with roundworms. In most cases, this migration causes no problems, and the infection is quickly eliminated by the animal’s immune system.
However, if a neonate is involved, or an animal with a compromised immune system, severe disease might result. In younger pets, diarrhea, abdominal pain, and weight loss are the most consistent clinical signs seen in an overwhelming case of coccidiosis.
Older pets might not show any signs at all. If tissue migration has occurred (toxoplasmosis), other signs might be seen, including fever, muscle soreness, and convulsions. A microscopic examination of a stool specimen will detect coccidia eggs if present.
Treatment consists of administering an anticoccidia drug in proper dosages. If dehydration is present, intravenous fluids are indicated to correct the disorder. Good sanitation practices are the best ways to prevent exposure to coccidiosis.
Routine stool checks performed by a veterinarian should also be utilized to ensure that dogs and cats remain parasite-free. As a zoonotic disease, toxoplasmosis is of significance, especially in pregnant women.