What is coccidiosis?

Coccidiosis is an infection with a one-celled protozoal organism called coccidia. Coccidia are not worms, but they are microscopic parasites that live within the cells of the intestinal lining. Despite their small size, they can be an important cause of illness, especially in puppies and kittens. While the term coccidiosis applies to infection with all organisms in this class, we most commonly use it to indicate an infection with Isospora (dogs and cats) or Eimeria (rabbits). Infection with Toxoplasma and Cryptosporidium will not be discussed in this handout.

How did my dog or cat get coccidia?

Oocysts (immature eggs) are passed in the feces. These eggs lie in the environment and eventually sporulate (mature) into a more developed oocyst that is infectious. If the sporulated oocyst is ingested (after grooming, eating grass, or chewing on a stick contaminated with the oocysts), it matures in the intestine and completes its life cycle. Alternatively, a mouse may ingest the oocysts, and dogs and cats can become infected if they ingest an infected mouse. These organisms tend to be species-specific – in other words, dogs are not affected by rabbit coccidia and vice versa.

What are the clinical signs?

While these parasites can be asymptomatic in adult animals, large numbers of organisms can lead to clinical problems. Severe diarrhea, bloody feces, dehydration, vomiting, weight loss, and abdominal pain can occur. While death is rare, it can occur with serious infections, especially in puppies, kittens, or ill animals.

How is coccidiosis diagnosed?

Coccidia are diagnosed by microscopic examination of your pet’s stool. Since your veterinarian is searching for eggs and shedding of eggs can be intermittent, more than one sample may be necessary to make a diagnosis. All pets should have a fecal intestinal parasite examination performed at least 1-2 times per year.

How is coccidiosis treated?

Fortunately, treatment is safe, simple, and relatively inexpensive. The most common medication is a sulfa-type antibiotic called sulfadimethoxine (Albon). This medication is generally given for 10 days, though longer therapy is occasionally required. Re-infection is common, so environmental management is important. Prompt disposal of all feces is essential, especially in yards, playgrounds, and public parks. Litter boxes should be scooped daily and cleaned thoroughly once weekly. A mixture of dilute bleach (1:10 dilution) can be used to clean litter boxes and contaminated toys or kennels. Always wash your hands thoroughly after handling feces or cat/rabbit litter.

Are coccidia organisms dangerous to humans?

No, Isospora and Eimeria are not infectious to humans, though both Toxoplasma and Cryptosporidium can be zoonotic.

Content prepared by St. Francis Animal Hospital, 1227 Larpenteur Ave. West, Roseville MN. 55113