Q. Your recent answer about cats causing toxoplasma in pregnant women made me want to ask a related question. I've heard that you can get a strep throat infection from dogs. Can this be true? I'm concerned becuse I often catch our dog licking my 3-year-old on the face.

A. It's possible, but extremely unlikely.

I know of one recent report that described four cases of strep throat infection in one family that was traced to their pet dog. While Fido may have been the culprit in that instance, strep infections, which are caused by the streptococcus germ, are almost always passed from one person to another.

Pet-related illness is an interesting but not well-publicized topic in medicine. You can get dozens of diseases from pets, although most are very uncommon. These diseases range from the familiar, such as rabies and infected dog bites, to unusual conditions that may be difficult to diagnose and treat.

Dogs can transmit various worms to people, as well as carry bacterial infections and the fungus that causes the skin rash known as ringworm. In addition to the toxoplasma infection you mention, cats are responsible for cat scratch fever, a bacterial infection producing swollen glands, which most often occurs in children who have been scratched or bitten by a cat.

Baby turtles have been known to give people salmonellosis, an intestinal infection resulting in fever and severe diarrhea. Rarely, parrots have transmitted psittacosis (from the Greek word for parrot) to their owners, which in people causes fever and pneumonia.

Here are some steps to follow to reduce your small risk of getting an illness from pets:

*Consult your veterinarian for any illness or unusual behavior in your pet.

*Have your cat or dog vaccinated against rabies, and follow your veterinarian's recommendations about other preventive measures.

*To protect small children from being bitten, don't leave them unsupervised around large dogs.

*Have a weaned puppy treated for worms twice, two weeks apart. (Pups and nursing bitches should be treated for worms at two, four, six, and eight weeks after the pups' birth.) Don't let your children play in areas where dogs and cats are allowed to roam freely, or where children may come into contact with animal droppings.

*Change your cat litter daily.

*Wear gloves when cleaning up animal droppings, and wash your hands afterwards.

*Don't let your pets eat wild prey, which may be infected with a contagious disease.

Q. In response to your answer on diabetes in pregnancy, I've heard that women with gestational diabetes are at risk for developing diabetes later in life. Could you tell me what percentage of women with gestational diabetes later become diabetic and whether the risk increases with the number of times you're pregnant? Is there anything I can do to minimize my chance of becoming diabetic?

A. Women with gestational diabetes -- diabetes Between 10 and 50 percent of women with gestational diabetes later become diabetic. that first develops during pregnancy -- are at increased risk for becoming diabetic later in life, but there may be some steps you can take to reduce your risk.

Between 10 and 50 percent of women with gestational diabetes later become diabetic. The risk increases more with your age than with the number of pregnancies you've had, although pregnancy itself stresses the body's metabolism and can lead to elevated levels of blood sugar, a sign of diabetes. The higher the level of blood sugar during pregnancy, the greater the chance of developing diabetes later.

Once you've been diagnosed as having gestational diabetes, it's important to be checked after pregnancy to see if you're still diabetic. This is done with a glucose tolerance test, which checks whether your blood sugar level rises above normal after drinking a glucose-rich drink.

You should have a glucose tolerance test about the time of your first visit after delivery. After that, your blood glucose level should be checked periodically to see if it's normal. It's especially important to be examined before another pregnancy to make sure you're not showing signs of early diabetes. If so, you'll need treatment, usually diet regulation, to try to prevent diabetes-related complications during pregnancy.

Preliminary studies suggest that dietary treatment after having had gestational diabetes helps prevent diabetes from occurring in the future. It's less clear whether losing excess weight and exercising regularly are beneficial preventive measures, though they do make sense. It's also uncertain whether avoiding medicines that have a tendency to raise your blood sugar is helpful in preventing future diabetes. These include oral contraceptives, thiazide diuretics (fluid pills) and steroids (such as prednisone).

It is clear, however, that it's important to diagnose and treat gestational diabetes, and prevent it if possible. Besides the harmful effects on the developing fetus I mentioned in an earlier column May 7 , there's some evidence that gestational diabetes leads to an increased risk of obesity and diabetes in exposed offspring later in life. More studies are needed to show whether this is a direct effect of diabetes during pregnancy or a manifestation of diabetes' tendency to run in families.