- Not a substitute for professional veterinary help.
If you’re reading this, you’re likely a cat owner who has been warned about the dreaded risk of toxoplasmosis, often because you or someone you know is pregnant or considering becoming pregnant.
But what is it? Let’s take a deeper look at what toxoplasmosis is, how it can impact both you and your pet cat, and answer some of the questions you might have about the disease and your risk for it.
Toxoplasmosis a parasitic infection caused by the single-celled Toxoplama gondii (T. gondii) parasite. It is among the most common parasites in mammals—which includes humans—and can affect most warm-blooded creatures including house pets. Many experts estimate that upwards of 80% of the human population could be infected with a mostly latent, or asymptomatic, form of the disease.
Toxoplasmosis is most often transmitted to humans by eating contaminated meat that is undercooked, through fecal matter of house cats, or by mother-to-fetus transmission during pregnancy.
In most cases, the T. gondii parasite causes few if any symptoms in humans and most people are unlikely to even realize that they’ve been infected. The most likely are flu-like symptoms—fever, muscle aches, swollen lymph nodes—that can persist for a few weeks to a few months before subsiding.
However, people with weakened immune systems such as HIV patients, pregnant women, chemotherapy patients, or the elderly and infants can be at risk for symptoms and complications if they contract toxoplasmosis.
For pregnant women and their fetuses, the symptoms can be especially devastating for the unborn fetus and can include miscarriage, stillbirth, and post-natal development of mental disability, vision impairment, or seizure, according to the Centers for Disease Control (CDC).
People with suppressed or compromised immune systems who are infected with T. gondii either before they became immunocompromised or after risk developing more serious complications, such as infection, high fevers, headaches, lightheadedness, confusion, compromised mobility, nausea, or seizure.
Cats usually become infected with toxoplasma by killing and eating infected rodents or from livestock, according to Cornell University College of Veterinary Medicine. Cats—both domestic cats and wild cats—are a “definitive host” for the parasite T. gondii. That means that the parasite actually reproduces and forms eggs inside of cats. These eggs manifest into cysts and oocysts which then exit the cat’s body in their feces.
Other mammals, such as rodents and humans, are what we call intermediate hosts. When we or they come into contact with these egg-carrying cysts and ingest them, we become hosts for the parasite to live. We can’t pass it on to other people except for mother-to-child transmission during pregnancy.
So how might toxoplasmosis present itself in your feline friend? The answer is, it probably won’t. Since cats are definitive hosts of the parasite, their body chemistry is particularly well-suited for fighting off infection.
On the rare occasion that symptoms do present in cats, they tend to present as loss of appetite, lethargy, or fever. Even more rarely a toxoplasma infection can cause issues in a specific organ. For example, yellowing of the skin in a liver infection, loss of vision in an eye infection, or loss of coordination and change in behavior if the infection is impacting the nervous system.
Toxoplasmosis is frequently transmitted between feline hosts and other mammals, including humans, so yes, you can get toxoplasmosis from your cat in addition to eating or handling tainted meat.
For most people, toxoplasmosis isn’t a concern. However, if you are pregnant or considering becoming pregnant, or if you have a compromised immune system, there is need for concern.
Many pregnant women are full of questions like, “What will toxoplasmosis do to an unborn baby?” or “Will toxoplasmosis harm my baby?” or “Do I have to get rid of my cat?”
The answers are complicated, but in general, you do not need to get rid of your cat, according to the CDC. However, since a toxoplasmosis infection can be passed between an unborn baby and mother, it is imperative that care and caution are taken when cleaning litter boxes.
If at all possible, someone else should handle cleaning litter boxes and that person should clean the litter box every day or as frequently as possible to limit the risk of infection.
If a pregnant person is changing a litter box, disposable gloves should be worn and thrown out after making contact with a litter box. They should also be certain to thoroughly wash hands with warm water and a strong soap frequently and after petting their cat or handling a litter box.
Once you have been infected with toxoplasmosis, it will always remain dormant within the tissues in your body and will not go away. Generally, most carriers will never become aware that they are even infected. For people exhibiting symptoms, these will usually clear up within a few weeks to months.
The only time a previous infection can cause a problem for a carrier is if his or her immune system is later compromised. Very rarely, this can cause the dormant parasite to be reactivated and cause infection.
There are many small steps you can take to ensure that you keep yourself protected from toxoplasmosis.
- Never eat undercooked meat. All ground meat should be heated to an internal temperature of at least 160°F and whole meats to at least 145°F with a minimum of three minutes of resting time before consumption.
- Always fully clean all kitchen items that have contact with raw meats—such as cutting boards and knives—with hot soapy water. It’s also a good idea to designate specific utensils for handling raw meats and others specifically for produce and other products.
- The Companion Animal Parasite Council recommends changing litter boxes daily to avoid the risk of infection in humans since the parasite itself needs 1-5 days of incubation in passed feces to actually become infectious to humans. Always wear disposable gloves when handling litter matter and thoroughly wash and dry hands afterward.
- If you’re pregnant or have an immune disorder, leave litter box duty to someone else if at all possible. If not, change litter daily and be sure to wear a glove and breathing mask. Fully dispose of litter and refuse in an outside, sealed trash can.
- Fully cover sandboxes or other areas that may be attractive to cats for use as a litter box when not in use.
- Keep your cat’s bedding clean and wash with hot water often if you are susceptible to infection.
- If you are immunocompromised, ask your doctor for testing to determine whether or not you are already a carrier of the parasite.
According to the CDC, treatment is not necessarily needed, especially if you are otherwise healthy and are not pregnant. If symptoms present at all, they generally clear up on their own with a few weeks to months. For people who are immunocompromised or pregnant, there are courses of antibiotics that can help treat symptoms. A treatment plan can be discussed with a healthcare professional. Treatment can help prevent infection in unborn babies, and both mother and child will need follow-up observation and care for some time following a toxoplasma infection.
For cats, who are generally asymptomatic, treatment is not generally warranted. However, if symptoms do present and are particularly severe, a veterinarian may recommend a course of treatment to help alleviate symptoms or treat secondary infections and symptoms.
Most cats will never display symptoms of a T. gondii infection, so it’s very rare for an owner to even be aware of toxoplasmosis infection in their pets. Even when an animal is infected, they can only transmit the parasite to others through their feces for one to three weeks after their initial infection.
So no, your cat will not always be a carrier. Cats can be re-infected throughout their lifetime, however, so it can be very difficult to know if or when you might be at risk for infection.
Toxoplasmosis sounds scary, and under the right circumstances, it can present a risk for certain individuals. But rest assured that with a bit of caution and foresight, it’s a risk that can be managed.