Toxoplasmosis in Cats: Signs, Pregnancy Risk and Prevention

What toxoplasmosis is and how cats catch it

Toxoplasma gondii is a single-celled parasite that can infect nearly all warm-blooded animals, including people. Cornell Feline Health Center explains that cats are its only definitive host, meaning the parasite can complete its full life cycle only in a cat's intestine. Cats usually become infected by eating infected mice, birds or other prey, or raw or undercooked meat.

After infection, the parasite multiplies in the gut and the cat sheds microscopic eggs, called oocysts, in its stool. Cornell notes that shedding typically starts 3 to 10 days after exposure and lasts about 10 to 14 days. The eggs are not infectious when first passed: they need 1 to 5 days in the environment to mature, but once they do they can survive in soil for over a year.

Signs of toxoplasmosis in cats

Most infected cats show no signs at all. When illness does occur, Cornell reports it is more likely in kittens and in cats whose immune systems are weakened, for example by FeLV or FIV. The most common signs are fever, loss of appetite and lethargy, which look like many other illnesses.

In more severe cases the parasite affects other organs. Lung involvement can cause fast or labored breathing, liver involvement can cause yellowing of the skin and gums, eye involvement can cause redness, cloudiness or changes in vision, and nervous system involvement can cause wobbliness, behavior changes or seizures. Any of these signs needs a vet visit, whatever the cause turns out to be.

When to call your vet today

Call your vet the same day if your cat has a fever, has stopped eating, or is unusually lethargic, especially if it hunts, eats raw food, or is a kitten or FIV- or FeLV-positive. Also call promptly for any change in the eyes, such as redness, squinting, cloudiness or a cat that seems not to see well.

If someone in your household is pregnant or has a weakened immune system and you are worried about your cat, call your vet for advice and talk to your own doctor too. Your vet can discuss your cat's lifestyle and risk, and the CDC encourages owners to raise these questions with their veterinarian.

When it's an emergency

Go to your vet or the nearest emergency vet immediately if your cat is breathing fast or with effort, breathing with its mouth open, has yellow gums or eyes, has a seizure, collapses, or suddenly loses its sight. These are serious signs in any cat. Cornell notes that the outlook is usually poor when toxoplasmosis affects the liver or lungs, which is another reason to act quickly.

A kitten that is weak, not eating, feverish or breathing hard also needs urgent care, since young cats are among those most likely to become seriously ill.

What you can safely do at home

Do not give your cat any medicine without your vet's direction. At home, the useful steps are about limiting exposure. Scoop the litter box every day: because the eggs take at least a day to become infectious, the CDC notes that daily changes reduce the chance of contact with infectious eggs. Wear gloves, put the waste in a sealed bag, and wash your hands with soap and water afterward.

Cornell recommends that pregnant or immune-compromised people hand litter box duty to someone else where possible. If that is not possible, gloves and thorough handwashing matter even more. Feed cooked commercial cat food rather than raw meat, keep cats indoors so they cannot hunt, and keep sandboxes covered.

Scooping the litter every day with the right litter accessories matters here, because the parasite's eggs need time in the litter before they can infect anyone.

What the vet will likely check

Diagnosis is based on your cat's history and signs together with blood tests for antibodies to Toxoplasma. Cornell notes that looking for eggs in a stool sample is not reliable, and that a definitive diagnosis requires examining tissue under a microscope. Your vet may also run general blood work and check the eyes closely.

Cats that are ill are treated with a prescription antibiotic, sometimes with anti-inflammatory medicine for eye or nervous system inflammation, and early treatment is preferred. Cornell notes that cats with eye or nervous system signs that improve within the first few days have a better outlook. There is currently no vaccine for cats or people.

Prevention and protecting people

The CDC lists the main ways people catch toxoplasmosis as eating undercooked meat or shellfish, eating unwashed produce, and accidentally swallowing the parasite from soil or cat stool. Cornell notes that infection is more often linked to food and gardening than to handling cats, and that the CDC no longer advises people to avoid cats. Cook meat to safe temperatures, wash fruit and vegetables, wear gloves when gardening, and wash your hands well.

For your cat, the most effective steps are keeping it indoors, feeding cooked or commercial food, preventing hunting and keeping it away from livestock areas. Anyone who is pregnant should ask their own healthcare provider about extra precautions.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.