• Coccidiosis is an intestinal condition caused by a single-celled parasite.
  • Dogs and cats swallow cysts containing the parasite from contaminated environments, usually during grooming.
  • Signs of coccidiosis include watery diarrhea with blood or mucus, and possibly vomiting and lethargy (tiredness).
  • Puppies and kittens are more severely affected than adult animals.
  • People cannot be infected with the coccidia that affect their pets.
  • Diagnosis is made by identifying the parasite cysts during a fecal exam.
  • Pets are usually treated with an oral medication for 5 to 10 days.

What Is Coccidiosis?

Coccidiosis is an intestinal condition caused by a microscopic, single-celled parasite. While there are several types of coccidia, dogs with this condition are usually infected with Isospora canis, while cats are infected with Isospora felis.

What Causes Coccidiosis?

Infected dogs and cats shed cysts containing the parasite in their stool. These cysts can survive in the environment for as long as a year. Other pets become infected by swallowing the cysts from a contaminated environment, usually during grooming. Dogs and cats can also contract the parasite by eating an infected rodent.

Once inside the pet’s digestive tract, the cysts break open, and the parasite enters the intestinal cells, where it reproduces. The cell eventually ruptures, releasing the parasites and damaging the intestinal lining.

What Are the Signs of This Condition?

Signs of coccidiosis include watery diarrhea that may be tinged with blood or mucus. Pets with this condition may also experience vomiting, a loss of appetite, and lethargy (tiredness). Puppies and kittens can be severely affected, exhibiting dehydration, weight loss, and, in some cases, death.

Older pets usually have milder signs. Some pets may show no signs at all but still shed the parasite cysts in their feces.

Is Coccidiosis Contagious?

The coccidia species that infect dogs do not infect cats, and vice versa. However, the cysts in the feces from one dog can infect another dog, and the cysts in the feces from one cat may be infective to another cat. People generally cannot become infected with the species of coccidia that affect dogs and cats.

How Is Coccidiosis Diagnosed?

A diagnosis of coccidiosis is made by identifying parasite cysts on a fecal exam. Since the cysts are often difficult to find on a fecal exam, your veterinarian may choose to treat your pet if there is a high suspicion of coccidiosis, even if no cysts are found. This precautionary treatment is not harmful to your pet.

Any new pet being introduced into the home should have a fecal sample tested as soon as possible to diagnose coccidiosis or other intestinal parasite infections. Your veterinarian may also recommend fecal tests during your pet’s regular physical examinations.

How Is Coccidiosis Treated?

Several oral medications may be used to treat this condition. Your pet will most likely require daily treatment for 5 to 10 days. If you have a multi-dog household, but only one dog shows signs of coccidiosis, it’s a good idea to treat the other dogs to prevent reinfection from other pets that may carry the parasite but show no signs. The same goes for multi-cat households.

Pets (particularly puppies and kittens) with severe dehydration may need fluid therapy.

How Can I Prevent Coccidosis?

To prevent your pet from being infected from parasite cysts in the environment, wash his or her bedding and clean the kennel area with an ammonia product. Pick up and dispose of feces as soon as possible, and keep your pet from hunting animals when outside.