Q: I have a compromised immune system, and my physician said I am at risk for toxoplasmosis, a disease humans and other animals share.
Tests show I don’t have toxoplasmosis, but I have a cat, and I’m told that cats can transmit the disease to humans. If my cat has toxoplasmosis, how will I know?
A: You probably won’t, so it’s best to do all you can to keep from getting the disease. Fortunately, you may keep your cat.
Toxoplasmosis (“toxo”) is caused by a one-celled parasite called Toxoplasma. A cat becomes infected after eating a rodent or other mammal, bird, fish, reptile or amphibian infected with Toxoplasma.
To prevent this step in disease transmission, confine your cat indoors to deter predation, and feed commercial dry and/or canned cat food, not raw food.
Most cats show no clinical signs when infected with toxo, but for the first few weeks after exposure, they shed toxo eggs, called oocysts (“OH-uh-sists”). These oocysts take over 24 hours to become infective, so if you scoop litter boxes at least once daily, you can avoid exposure to infective oocysts. Wear a mask and disposable gloves while scooping, and wash your hands afterward.
Toxoplasma oocysts shed into soil and sand are infective, so wear gloves when gardening, and wash your hands after gardening or playing in sand. Wash all vegetables and fruit before eating them.
Toxoplasma oocysts ingested by shellfish, fish, pigs, sheep, deer and other animals encyst in their muscles and can cause disease in humans who eat them. So use a thermometer to ensure that your food is cooked thoroughly, and wash cutting boards and utensils in hot, soapy water.
In addition, don’t drink unpasteurized milk or eat cheese made from raw milk.
You can continue to enjoy your cat by following these recommendations to prevent toxoplasmosis.
Lee Pickett, V.M.D. practices companion animal medicine. Contact her at firstname.lastname@example.org.