Toxoplasmosis in cats is an infectious disease caused by the parasite Toxoplasma gondii. Toxoplasma is one of the most common parasites in cats and can infect nearly all warm-blooded animals. More than 60 million people in the U.S. are thought to be infected with Toxoplasma gondii, according to Cornell University's College of Veterinary Medicine. Although cats are a necessary part of the life cycle of Toxoplasma, the parasite rarely causes any sickness in cats.
Let's take a closer look at toxoplasmosis as well as possible signs that your cat may have this disease.
What is Toxoplasmosis in Cats?
Toxoplasma gondii is one of the most common internal parasites in cats. While Toxoplasma can infect any warm-blooded animal, including birds, cats are the definitive host of toxoplasma; therefore, this parasite can only replicate in cats.
Toxoplasma is shed in the feces of infected cats. Cats become infected with Toxoplasma by eating anything contaminated by feces from other infected cats. They can also become infected by eating rodents, birds or other small warm-blooded animals infected with Toxoplasma. Once a cat becomes infected with Toxoplasma, the parasite grows and replicates in the gastrointestinal tract. Cats that are newly infected with Toxoplasma are considered contagious for about two weeks after the initial infection.
Cats with compromised immune systems — such as cats infected with the leukemia virus, feline immunodeficiency virus (FIV), the virus that causes feline infectious peritonitis (FIP), Mycoplasma haemofelis, cats that are receiving chemotherapy or cats that have had a kidney transplant — are at an increased risk for developing severe or life-threatening complications associated with Toxoplasmosis.

Symptoms of Toxoplasmosis in Cats
After being exposed to Toxoplasma, most cats become immune and may never show any signs. A smaller proportion of cats may develop mild diarrhea and lose their appetite. Toxoplasma can also negatively impact a cat's liver, lungs and nervous system. Additional signs associated with Toxoplasma include:
- Fever
- Difficulty breathing
- Vomiting
- Weight loss
- Abdominal distention due to fluid retention
- Neurological signs, including seizures, incoordination, circling, head tilt
- Red eyes, swollen eyes, blindness
If you think your cat might be infected with toxoplasma, schedule an appointment with your local veterinarian as soon as possible. To protect people and other warm-blooded animals in the household, use gloves when cleaning the litter box, prevent any other animals from accessing the litter box and always wash your hands after cleaning the box. Women who are pregnant should not clean the litter box.
Toxoplasmosis in Kittens
Kittens exposed to the parasite while still in the womb are the most vulnerable; they're more likely to show signs than adult cats. These kittens are often stillborn or die before weaning. If a kitten survives, they often won't eat, will develop a high fever that doesn't respond to antibiotic therapy, and suffer from severe respiratory and neurological complications as well as liver problems.
