Take Precautions To Avoid Infection

By Dr. Greg Perrault, DVM

It seems like many of my clients and friends are either pregnant or becoming grandparents.

A frequent concern I get from pregnant women is that their cat might be dangerous to them and their unborn child.

The concern they have is a disease called Toxoplasmosis.

Toxoplasmosis is a disease caused by a microscopic parasite called Toxoplasma gondii. Since its discovery in 1908, toxoplasmosis has been found in virtually all warm-blooded animals, including people.

There are two populations that are at high risk for infection with Toxoplasma; pregnant women and immunodeficient individuals, such as people with HIV or people undergoing chemotherapy.

A woman who is newly infected with Toxoplasma during pregnancy can pass the infection to her unborn child. The woman may not have symptoms, but there can be severe consequences for the unborn child, such as diseases of the nervous system and eyes.

The major way people contract toxoplasmosis is by eating undercooked meat.

In fact, toxoplasmosis is considered to be the third leading cause of death attributed to food-borne illness in the United States.

Another way to contract toxoplasmosis is exposure to cat feces infected with the parasite. Cats become infected from eating mice, birds and other small animals that are infected with the Toxoplasma parasite. For indoor cats, the most likely source is a raw meat diet.

When a cat is exposed to Toxoplasma parasites through the consumption of infected meat or tissues, the cat can eventually excrete millions of oocysts (eggs) in its feces each day.

This release of oocysts can continue for up to two weeks. Oocysts are not immediately dangerous when they are passed from the cat. They need to sporulate or “ripen” for about 24-48 hours. Since most cats do not leave feces on their fur for two days, it is unlikely that humans become infected from direct contact with cats themselves.

People can be infected by:

• Accidental ingestion of oocysts after cleaning a cat’s litter box when the cat has shed Toxoplasma in its feces.

• Accidental ingestion of oocysts after touching or ingesting anything that has come into contact with a cat’s feces that contain Toxoplasma.

• Accidental ingestion of oocysts in contaminated soil (e.g., not washing hands after gardening or eating unwashed fruits or vegetables from a garden).

• Drinking water contaminated with the Toxoplasma parasite.

To prevent exposure to Toxoplasma, the CDC recommends these following steps, especially during pregnancy:

• Change litter daily before any Toxoplasma oocysts can “ripen” and become infectious. Dispose of used litter safely, preferably in a sealed plastic bag.

If pregnant, avoid changing the litter box if possible (or use rubber gloves).

• Wash vegetables thoroughly before eating, especially those grown in backyard gardens. Boil water from ponds or streams before drinking when camping or hiking.

• Cover sand boxes when not in use to discourage cats defecating in them.

• Wash hands with soap and water after working with soil or after handling raw or undercooked meat.

• Cutting boards, knives, and the sink and counters should be washed thoroughly after cutting meat.

• When cooking, avoid tasting meat before it is completely cooked.

• Cook meat thoroughly until the internal temperature reaches 152ºF (66ºC) in a conventional oven.

Microwaving is not a sure way to kill Toxoplasma in meat.

• Do not let your cat hunt birds or mice.

• Do not feed a raw meat diet to your cat.

With simple precautions you can enjoy your cat and avoid toxoplasmosis infection. If you still have questions about this parasite, consult your veterinarian.

Dr. Greg Perrault owns and operates Cats & Dogs Animal Hospital in Long Beach.