Be careful with cat litter

Last week part of my column included material from one I wrote two and a half years ago on veterinary practice names. It has come to my attention that since the original column was written, the American Veterinary Medical Association (AVMA) has made revisions to its naming guidelines. Among the changes, they no longer define a difference between an “animal hospital” and a “veterinary clinic.” The previous definition of an “animal medical center” is now said to define a “veterinary teaching hospital.”
The changes themselves demonstrate the premise of the original column, which was that the name on the sign out front may or not accurately reflect the care delivered inside. Realistically, how many practices changed their names when the guidelines were revised? The AVMA should be commended for recommending uniform naming standards. However, pet owners should choose their veterinarian based on the practice itself, not the name in the phonebook.

If you are interested in reading the full guidelines for naming veterinary facilities, please visit http://www.avma.org/issues/policy/naming_facilities.asp... and check back regularly.
Q: When I got pregnant, my obstetrician instructed me not to clean the cat’s litter pan. Why?

A: Cats can be a carrier of a single-celled parasite called Toxoplasma gondii. If a pregnant woman who has never been exposed to the parasite is infected during a very specific period of her baby’s development, severe birth defects or fetal death can occur.

In the United States, as much as 40 percent of the population is seropositive for Toxoplasma gondii. This means that almost half of us have had the infection and not even known it. Exposure rates in France and Germany are as high as 80 percent. Toxoplasmosis generally causes no symptoms or a brief flu-like illness. The illness can be severe in patients with compromised immune systems, including people with AIDS. The good news is that the large percentage of women who are already seropositive before becoming pregnant has almost no risk of problems with their babies due to toxoplasmosis.

Another piece of good news is that there is very little risk of contracting this illness from your cat. Most infections occur from consuming undercooked meat. Cat owners are no more likely than the general population to test seropositive. Vegetarians are infected less than the rest of us. Those of us who work in veterinary offices are also at higher risk.

If otherwise healthy, infected cats rarely shed the infective form of the parasite, the oocyst or egg. It is typical for an infected cat to shed eggs for ten days or less during its entire life. The odds of one of these ten days happening during the critical points of a pregnancy in a previously seronegative woman are quite small. In addition, once passed in the cat’s feces, the oocyst requires at least 24 hours to mature before posing any risk to people. Therefore, asking someone else to handle litter pan duty AND having them clean it at least once daily will minimize the risk.

You can also reduce risk by avoiding undercooked meat, especially pork or mutton. Meat that has been cooked only in the microwave may be a higher risk due to uneven heating.

Unpasteurized dairy products, especially goat milk, may cause infection. Infection risk can also be lowered by regular hand-washing and by avoiding gardening, especially in areas where cats defecate. 

To reduce your cat’s risk of exposure to toxoplasmosis, you should keep her indoors and feed only cooked commercial pet food (i.e. no raw diets). Cats acquire the infection primarily through hunting. Infected cats shed oocysts at a significantly higher rate when they are co-infected with certain viruses. The risk for these viral infections can be minimized or eliminated by keeping a cat indoors.

Having a baby is an awesome responsibility. Taking care of your health while pregnant plays a vital role in the development of your child. It is important to carefully follow the advice of your obstetrician regarding toxoplasmosis. When seeking to reduce the risk of your cat acquiring this parasite, or seeking to minimize the possibility of oocyst shedding, be sure to consult your family veterinarian.

The Centers for Disease Control and Prevention publishes a very informative web site with more details about toxoplasmosis. It can be found at http://www.cdc.gov/toxoplasmosis.

Dr. Watts is a companion animal general practitioner and owner of Clevengers Corner Veterinary Care. He can be reached through ClevengersCorner.com or by calling 428-1000.