Sarcocystis Infection in Cats


PetMD Editorial

Published Oct. 17, 2012

Sarcocystosis in Cats

The causative agent of sarcocystosis (Sarcocystis) is the same organism that causes equine protozoal meningitis. Cats that live around horses and other herbivores (cattle, swine, etc.) may serve as a reservoir for infection for these animals. Symptoms in infected cats are rare however.

Sarcocystosis can occur in both dogs and cats. If you would like to learn how this type of infection affects dogs, please visit this page in the petMD health library.

Symptoms and Types

Symptoms in cats are rarely seen but may include:

  • Lack of appetite
  • Weight loss
  • Diarrhea, potentially bloody diarrhea
  • Dehydration
  • Depression
  • Paralysis


A cat may be infected by eating raw meat contaminated with Sarcocystis organisms.


Occasionally, Sarcocystis organisms can be seen in the feces on microscopic fecal examination. However, in most instances, diagnosis is accomplished by finding the organism on histopathology in tissues such as the lungs, liver, kidney, spleen, brain and/or muscle.

More specialized testing such as immunohistochemistry and PCR may be available at some research facilities but are not widely available outside of a research setting.


No definitive treatment for sarcocystosis exists. Treatments such as clindamycin or sulfadiazine may be tried if sarcocystosis is suspected or diagnosed.


Do not allow your cat to eat raw or uncooked meat.

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health