Toxoplasmosis and Pregnancy

Toxoplasmosis is a common parasite in cats. Cat lovers who are considering pregnancy are often warned by others to get rid of their cat before they get pregnant, in order to avoid getting toxoplasmosis, which is carried by cats. In most cases, this is simply unnecessary. It is much harder to become infected with toxoplasmosis than you may think.

"Toxoplasmosis is an infectious disease caused by the parasite Toxoplasmosis gondii" said Dr. Sally Purcell, feline internal medicine resident at Texas A&M College of Veterinary Medicine & Biomedical Sciences. "Toxoplasmosis is one of the most common parasite infections, and rarely causes significant disease in cats or other warm-blooded species. Both indoor and outdoor cats can be carriers, but it is less likely that an indoor cat will be a carrier."

If your cat is a carrier of the toxoplasmosis parasite, you will most likely never know. The cat may get sick, but in most cases the parasite will be carried in the muscle or brain, without negatively affecting the animal. Since the parasite is carried inside a cat, owning an infected cat will not cause direct infection to humans.

"Cats definitely play an important role in the spread of toxoplasmosis. They become infected with the parasite by eating infected rodents, birds, or anything contaminated with feces from another cat that is releasing the parasite" said Purcell. "After a cat is infected, it can release the parasite in its feces for up to two weeks. The parasite can live in the environment for several months and contaminate soil, water, fruits, vegetables, sandboxes, litter boxes, or anywhere an infected cat may have defecated. People become infected with toxoplasmosis by eating food, drinking water, or accidentally swallowing soil that has been contaminated with infected cat feces."

Eating raw or undercooked meat that has been infected with toxoplasmosis is another way to become infected. All meat should be cooked to an internal temperature of 160 degrees Fahrenheit. If a pregnant mother becomes infected, her unborn child will also be infected. It is advised by veterinarians to not clean out your cat's litter box, while pregnant, since you cannot know for sure if your cat is infected. Those with weakened immune systems should be particularly careful; toxoplasmosis will cause severe illness to a person with a weak immune system.

"Most of the people infected with toxoplasmosis are unaware of its presence in their body" said Purcell. "When the illness occurs it is usually mild, some people may experience flu-like symptoms, with swollen lymph nodes, or muscle aches and pains that last for several weeks or longer. Some people, like cats, show no symptoms."

Toxoplasmosis can severely affect an unborn child, so expecting mothers should be particularly cautious when around strange cats. If a pregnant mother becomes infected with the parasite for the first time, right before or during pregnancy, the infection can be passed to the child. Most infants who are infected while in the womb show no symptoms at birth, but may develop severe symptoms such as blindness or mental retardation later in life. A small percentage of infected newborns have brain or eye damage at birth.

An important thing to note is if a woman has been infected prior to conception, the infant will be protected because the mother is immune. Some experts may suggest waiting for six months after a recent infection to become pregnant. If a woman is already pregnant, she should avoid stray cats, especially kittens, cover outside sandboxes, do not get a new cat while pregnant, and change (or have someone else change) your cat's litter box daily because the parasite will not become infectious until one to five days after it is discarded in the feces.

ABOUT PET TALK

Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University.  Stories can be viewed on the Web at http://tamunews.tamu.edu.

Suggestions for future topics may be directed to cvmtoday@cvm.tamu.edu.