Toxoplasmosis in Cats: Risks, Pregnancy & Facts

Toxoplasmosis is an infection caused by the microscopic parasite Toxoplasma gondii. Cats are the parasite's definitive host, which means they are the species that can shed the infectious egg-like stage, called oocysts, in their stool. Even so, most infected cats never look sick.

When illness does happen, it can affect the lungs, liver, eyes, nervous system, or digestive tract. Kittens and cats with weakened immune systems are at higher risk for more serious disease. A healthy adult cat may carry the parasite and show no outward signs at all.

This condition also matters because it is zoonotic, meaning it can affect people. The biggest concern is for people who are pregnant for the first time during exposure, or those who are immunocompromised. Still, the risk is often misunderstood. Cats do not continuously shed infectious oocysts, and good litter box hygiene makes household transmission less likely.

For many pet parents, the most helpful takeaway is this: a cat in the home does not automatically mean high risk. Understanding how the parasite spreads, when symptoms matter, and what prevention steps work can help you make calm, informed decisions with your vet.

Cats most often become infected by eating infected prey such as rodents or birds, or by eating raw or undercooked meat that contains tissue cysts. After a first infection, a cat may shed oocysts in stool for a limited time. Those oocysts usually need 1 to 5 days in the environment before they become infectious, which is why daily litter box cleaning matters.

Outdoor hunting raises exposure risk. Feeding raw diets can also increase risk for both cats and people in the household. In contrast, indoor cats that eat cooked commercial diets and do not hunt are generally less likely to become newly infected.

Not every exposed cat becomes sick. Healthy adult cats often control the infection well. Clinical disease is more likely in kittens and in cats with weakened immune defenses, including some cats with feline leukemia virus, feline immunodeficiency virus, or other serious illness.

For people, infection is not only about cats. Human exposure can also happen through undercooked meat, contaminated soil, unwashed produce, or contaminated water. That is one reason pregnancy counseling should focus on the whole picture, not the litter box alone.

Diagnosing toxoplasmosis in cats usually takes a combination approach. Your vet will start with your cat's history, including hunting behavior, raw food exposure, immune status, and current symptoms. A physical exam helps identify which body systems may be involved, such as the lungs, eyes, or nervous system.

Testing often includes routine bloodwork and sometimes imaging like chest X-rays if breathing signs are present. Vets may also use antibody testing to look for evidence of exposure. These results can be helpful, but they do not always prove that toxoplasmosis is the reason a cat is sick right now.

In some cases, your vet may recommend additional testing of body fluids, feces, or tissues, especially if the diagnosis is unclear or the cat is severely ill. Because many healthy cats have been exposed in the past, test interpretation can be tricky. That is why your vet usually combines lab results with symptoms and response to treatment.

If someone in the home is pregnant or immunocompromised, your vet may also talk through practical risk reduction. Testing a healthy cat is not always the most useful next step, so individualized guidance matters.

Prevention starts with reducing exposure. Keep cats indoors when possible so they are less likely to hunt infected prey. Avoid feeding raw or undercooked meat. Commercial cooked diets are a practical way to lower risk for both cats and people in the home.

Clean the litter box every day. This matters because oocysts shed in stool usually need 1 to 5 days before they become infectious. Wear gloves if needed, wash hands well afterward, and disinfect scoops and surrounding surfaces routinely.

If you are pregnant or immunocompromised, ask someone else to handle litter box duty when possible. If that is not realistic, use gloves and wash hands carefully afterward. Also focus on food safety: cook meat thoroughly, wash produce, avoid unpasteurized foods, and wear gloves while gardening.

Most families do not need to rehome a cat because of pregnancy. A calmer and more accurate plan is to combine daily litter box hygiene, indoor living, safe feeding practices, and regular veterinary care. If your household has special medical concerns, your vet and physician can help tailor the safest routine.