Coccidia in dogs and cats, from the Companion Animal Parasite Council.

Coccidia in Dogs (see below for the section on cats).

Coccidia are tiny single-celled parasites that live in the wall of your dog’s (or cat's) intestine. They are found more often in puppies, but they can also infect older dogs (and cats).  Dogs become infected by swallowing soil that contains coccidia or other substances in the environment that may contain dog feces.

How will coccidia affect my dog?

Coccidiosis, the disease caused by coccidia, may not cause any signs in dogs but is usually more serious in puppies. The most common sign of coccidiosis is diarrhea.  More severe infections can cause bloody diarrhea. Severe infections, especially in puppies, can kill them.

How do I prevent my dog from getting coccidia?

Coccidial infections can be prevented by removing your dog’s feces regularly from your yard or other areas where the dog goes to the bathroom. Because coccidia are found most often in puppies, it is important to have puppies examined for the parasite as soon as possible. Your veterinarian can perform a fecal test to diagnose coccidiosis. If your dog is infected with coccidia, your veterinarian is able to give it effective medications.

Can my cat get coccidia from my dog?

A dog infected with coccidia cannot pass the infection to cats and vice versa. Coccidial infections occur only by swallowing the coccidia in soil or dog feces.

Coccidia in Cats

Coccidia are tiny single-celled parasites that live in the wall of your cat’s (or dog's) intestine. They are found more often in kittens, but they can also infect older cats.

Cats become infected by swallowing soil that contains coccidia or other substances in the environment that may contain cat feces Also, it is possible that rodents could eat the coccidia and contract a “resting” stage of the parasite. Cats that are old enough to hunt could then be infected when they hunt and eat these animals. Cats are more likely to get infected with coccidia by this method than dogs are.

How will coccidia affect my cat?

Coccidiosis, the disease caused by coccidia, is usually more serious in kittens but can occur in older cats. The most common sign of coccidiosis is diarrhea.  Severe infections, especially in kittens, can kill them.

How do I prevent my cat from getting coccidia?

Coccidial infections can be prevented by cleaning your cat’s litter box regularly and by preventing your cat from hunting. Because coccidia are found most often in kittens, it is important to have kittens examined for the parasite as soon as possible. Your veterinarian can perform a fecal test to diagnose coccidiosis. If your cat is infected with coccidia, your veterinarian is able to give it effective medications.

Can my dog get coccidia from my cat?

A cat that is infected with coccidia cannot pass the infection to dogs and vice versa. Coccidial infections occur only by swallowing the coccidia in soil or cat feces or by eating intermediate hosts.