The most common reason pregnant women are told to "get rid of the cat" is toxoplasmosis. The advice is given by obstetricians, by mothers-in-law, by well-meaning friends, by internet forums, and sometimes by the woman's own doctor without explanation. The advice is also almost always wrong. The actual risk of contracting toxoplasmosis from a house cat is low, the actual transmission routes are specific and manageable, and the actual reasons to test or take precautions have nothing to do with getting rid of the cat. This article is the practical view from the consultant's chair, written for the pregnant woman who is worried and the partner who is trying to help.
We will go through what toxoplasmosis actually is, how it is actually transmitted, the real risk level from a house cat, the precautions that matter, the precautions that do not matter, the role of testing, the common misconceptions, and the four mistakes that lead to unnecessary rehoming of cats during pregnancy.
What toxoplasmosis actually is
Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii. The parasite has a complex life cycle with three forms:
- Tachyzoite: the rapidly dividing form, present during active infection
- Bradyzoite: the slowly dividing form, present in tissue cysts during chronic (latent) infection
- Oocyst: the environmentally resistant form, shed in the feces of infected cats
The parasite can infect virtually all warm-blooded animals, including humans, but the only species in which the parasite can complete its sexual reproductive cycle is the cat — both domestic cats and other felids. The cat is the definitive host. Everything else is an intermediate host.
In healthy adult humans, toxoplasmosis infection is usually asymptomatic or produces mild flu-like symptoms (fatigue, muscle aches, low-grade fever, swollen lymph nodes) that resolve within a few weeks. Most people who have been infected do not know they have been infected. Once infected, the person has lifelong immunity and will not be infected again.
In pregnant women, the situation is different. If a woman is infected for the first time during pregnancy (or within a few months before pregnancy), the parasite can cross the placenta and infect the fetus. The risk and severity depend on when in the pregnancy the infection occurs:
- First trimester infection: low transmission rate to the fetus (roughly 10 to 15%), but severe outcomes if transmission occurs (severe neurological damage, miscarriage, stillbirth)
- Second trimester infection: higher transmission rate (roughly 25 to 30%), moderate to severe outcomes (chorioretinitis, hydrocephalus, intracranial calcifications)
- Third trimester infection: highest transmission rate (roughly 60 to 70%), but the outcomes are generally milder (most infected infants are asymptomatic at birth, although some develop chorioretinitis or learning disabilities later in childhood)
The crucial point: the risk to the fetus is from a primary infection during pregnancy. A woman who was infected before pregnancy has lifelong immunity and cannot transmit the parasite to the fetus. The woman who has never been infected is at risk of a primary infection during pregnancy, but this is a manageable risk, not a reason to get rid of the cat.
The actual transmission routes
The parasite is transmitted to humans through three routes:
- Ingestion of tissue cysts in undercooked meat. This is the most common route of transmission worldwide. Undercooked pork, lamb, and game meat are the highest-risk foods. A person who eats rare lamb or undercooked pork is at much higher risk of toxoplasmosis than a person who handles cat litter. This is the transmission route that matters most for pregnant women who eat meat.
- Ingestion of oocysts from cat feces (or contaminated soil, water, or food). Oocysts are shed in the feces of infected cats for about 1 to 3 weeks after the cat's first exposure to the parasite. After that initial shedding period, the cat develops immunity and does not shed oocysts again. The oocysts require 1 to 5 days in the environment (in warm, moist conditions) to become infective. Fresh cat feces are not infective; only feces that has been sitting for at least 24 hours is a risk. The oocysts can survive in soil for months and can contaminate vegetables, fruits, water, and unwashed hands.
- Congenital transmission from mother to fetus during pregnancy. Only relevant if the mother has a primary infection during pregnancy.
The actual contribution of cat ownership to toxoplasmosis risk is small. Studies in the US and Europe have consistently shown that the majority of toxoplasmosis cases in pregnant women are from food (undercooked meat, unwashed vegetables) rather than from cats. The cat that has been indoors its whole life, eating commercial cat food, has a very low probability of being infected and shedding oocysts. The cat that goes outdoors and hunts is at higher risk, but the actual risk to the owner is still lower than the risk from the food in the refrigerator.
The real risk level from a house cat
Let me be specific about the risk.
For a woman who has never been infected with toxoplasmosis (seronegative), the probability of contracting toxoplasmosis from her indoor house cat during pregnancy is roughly 1 in 1,000 to 1 in 10,000, depending on the study. This compares to:
- The risk of contracting toxoplasmosis from undercooked meat during pregnancy: roughly 1 in 100 to 1 in 1,000 (much higher)
- The risk of contracting listeriosis from deli meat during pregnancy: roughly 1 in 8,000 (similar)
- The risk of being struck by lightning in a given year: roughly 1 in 1,000,000 (much lower)
The cat is one of the smaller risks. The food in the kitchen is a much bigger risk. The advice to "get rid of the cat" while continuing to eat rare lamb is reversing the actual risk order.
The precautions that matter
For a pregnant woman who owns a cat and wants to minimise the risk of toxoplasmosis:
Precaution 1: Have someone else clean the litter box. This is the single most effective precaution. If the pregnant woman does not clean the litter box, she is not exposed to the oocysts. The partner, a family member, or a hired pet sitter can do the daily cleaning. If the woman must clean the litter box herself, she should wear gloves, wash her hands thoroughly afterwards, and clean the box daily (so the feces do not have time to sporulate and become infective).
Precaution 2: Clean the litter box daily. Oocysts require 1 to 5 days in the environment to become infective. Daily cleaning removes the feces before they become a risk. The woman who cleans the box daily is exposed only to fresh (non-infective) feces, which is essentially a zero-risk activity.
Precaution 3: Wash hands after handling the cat, especially before eating. Routine hygiene. Not specific to toxoplasmosis, but useful for many reasons.
Precaution 4: Do not feed the cat raw or undercooked meat. Cats fed raw or undercooked meat are at higher risk of being infected with T. gondii and shedding oocysts. The cat fed commercial cat food (cooked kibble or canned) is at much lower risk.
Precaution 5: Keep the cat indoors. Indoor cats are at much lower risk of contracting toxoplasmosis than outdoor cats. The indoor cat is exposed only to commercial food and indoor pests, which carry very low T. gondii risk. The outdoor cat that hunts rodents and birds is at much higher risk.
Precaution 6: Avoid raw or undercooked meat in the woman's own diet. This is the higher-yield precaution. Undercooked pork, lamb, and game are the most common source of T. gondii for pregnant women. Cooking meat to an internal temperature of 67°C (153°F) kills the tissue cysts. The woman who eats well-cooked meat has dramatically reduced risk.
Precaution 7: Wash vegetables and fruits thoroughly. Vegetables and fruits can be contaminated with oocysts from soil (if grown in contaminated soil) or from water used for irrigation. Thorough washing removes the contamination.
Precaution 8: Wear gloves when gardening. Soil can be contaminated with oocysts from outdoor cat feces. The woman who gardens without gloves is exposed to the soil and any oocysts in it. Gloves and hand washing prevent exposure.
The precautions that do not matter
Avoiding petting or holding the cat. The cat's fur does not carry infective oocysts. Petting and holding the cat is a zero-risk activity for toxoplasmosis (and is good for the cat and the woman's mental health during pregnancy).
Avoiding the cat sleeping on the bed. Similarly zero risk. The oocysts are in the feces, not on the fur.
Rehoming the cat. This is unnecessary in essentially all cases, as discussed above.
Having the cat tested for toxoplasmosis. A positive test on the cat means the cat has been exposed to T. gondii at some point in its life. It does not mean the cat is currently shedding oocysts. A negative test does not rule out future exposure. Cat testing is not useful for risk management in pregnancy.
Having the cat bathed weekly. Oocysts are not present on the fur. Bathing does not change the risk.
The role of testing in the woman
The most useful test in pregnancy is the toxoplasmosis IgG and IgM antibody test. This test tells the woman whether she has been previously infected (IgG positive, IgM negative — immune, no risk to fetus), recently infected (IgG positive, IgM positive — possible primary infection, needs further workup), or never infected (IgG negative, IgM negative — at risk of primary infection, should take precautions).
Many obstetricians now test for toxoplasmosis immunity at the first prenatal visit. The result guides the precautions:
- IgG positive, IgM negative: immune. No precautions needed beyond standard hygiene.
- IgG positive, IgM positive: possible recent infection. Needs confirmation testing (avidity test) to determine when the infection occurred. If recent, there is a risk to the fetus and further testing (amniocentesis, fetal ultrasound) is needed.
- IgG negative, IgM negative: at risk. Take the precautions above.
The IgG-negative woman is the one who needs the precautions. The IgG-positive woman is already immune and does not need to change anything about her relationship with the cat. The information is useful, and the test should be done.
The role of the partner
Toxoplasmosis in pregnancy is a couples issue, not a cats issue. The partner who insists on rehoming the cat is missing the actual risk. The partner who takes over the litter box cleaning, who cooks the meat thoroughly, who washes the vegetables, is the partner who is actually reducing the risk.
The cat is the easy target because it is a tangible, visible presence. The undercooked lamb chop is invisible. The garden soil is invisible. The unwashed salad is invisible. The cat is right there, on the couch, looking pregnant-and-worried-owner in the face, and the natural human response is to remove the visible threat. The actual threat is in the kitchen. The partner who understands this can redirect the energy to the higher-yield precautions.
The common misconceptions
Misconception 1: "You can get toxoplasmosis just from being around cats." No. The oocysts are in the feces, not on the fur or in the saliva. Being around a cat is not a risk.
Misconception 2: "Indoor cats cannot get toxoplasmosis." Indoor cats have a much lower risk than outdoor cats, but they can still be infected through commercial food (rare but possible) or through contamination brought in on shoes. The risk is small but not zero.
Misconception 3: "A cat that has been infected once is contagious forever." No. The cat sheds oocysts only during the primary infection, for 1 to 3 weeks. After that, the cat develops immunity and does not shed again. A cat that was infected 5 years ago is not currently shedding.
Misconception 4: "If you have a cat, you have to get rid of it during pregnancy." No. The actual risk is manageable with simple precautions. Rehoming the cat is unnecessary.
Misconception 5: "Vegetarians cannot get toxoplasmosis." Not true. The undercooked meat route is one route, but the cat feces and contaminated soil/water routes are also possible. Vegetarians who garden without gloves or who eat unwashed vegetables can still be infected.
The four mistakes
Mistake 1: Rehoming the cat unnecessarily. The pregnant woman is told to get rid of the cat. The cat is rehomed or surrendered to a shelter. The woman is now at higher risk of depression and loneliness during pregnancy, and the cat is now in a shelter. The actual risk of contracting toxoplasmosis from the cat was always low. The harm of the rehoming is greater than the harm of the (small) continued risk.
Mistake 2: Ignoring the food and soil risks while focusing on the cat. The woman gives away the cat and continues to eat rare lamb. She is now at much higher risk of toxoplasmosis from the food than she was from the cat. The risk has been increased, not decreased.
Mistake 3: Not testing the woman's IgG status. The IgG test tells the woman whether she is at risk of primary infection. The IgG-positive woman can stop worrying. The IgG-negative woman knows to take the precautions. The test is inexpensive, widely available, and useful. Skipping it is missing a key piece of information.
Mistake 4: Making the cat's life miserable during pregnancy. The pregnant woman is so worried about toxoplasmosis that she confines the cat to one room, stops petting it, stops playing with it, and generally withdraws affection. The cat is stressed, the woman's mental health suffers, and the bond between them is damaged. The actual risk from petting, holding, and being near the cat is zero. The risk from withdrawing affection is real (depression, anxiety, and the cat developing behavior problems from the stress).
Closing the loop
The cat is not the threat. The food and the soil are the threats. The pregnant woman who keeps the cat, who has someone else clean the litter box, who cooks the meat thoroughly, who washes the vegetables, and who gardens with gloves, has very low risk of contracting toxoplasmosis. The woman who gives away the cat and continues to eat rare lamb has higher risk. The information is not complicated. The advice to rehome the cat is wrong. The pregnant woman who understands the actual risk can keep the cat, manage the small remaining risk, and have a healthy pregnancy and a healthy cat.
