One year ago, we adopted a 4-year-old spayed female schnauzer. She has been fed a popular commercial adult dog food and had her teeth cleaned several months ago. Soon after, she developed tartar on her teeth again with resulting bad breath. Can diet or any special care help her?

The tartar on her teeth is a sign of periodontal infection. By having her teeth cleaned, you were treating the infection and preventing more serious problems such as destruction of the teeth and gums and systemic disease.

I am not a big fan of most popular commercial diets. Most contain animal byproducts and chemical preservatives and additives. These ingredients are not the most nutritious for our pets; many holistic veterinarians believe these diets contribute to chronic illnesses we see in dogs and cats.

I prefer either a homemade diet or one of the newer natural, holistic processed foods. With any processed foods, supplementation with whole-food supplements, enzymes, green foods, enzymes and fresh veggies can increase nutritional value.

The only really good thing you can do to decrease the need for frequent professional dental scalings is a daily brushing of your pet’s teeth. Your veterinarian can show you how to do this.

I am interested in determining if my 3-year-old spitz is pregnant. Is there a quick and easy way to do this? Her veterinarian is recommending an ultrasound examination, but wouldn’t a simple X-ray be cheaper?

There are several things that can be done to determine if your dog is pregnant.

Abdominal palpation is a procedure that involves your doctor feeling the dog’s abdomen to detect fetal puppies. The procedure is most accurate in dogs that are at least halfway through their pregnancy and have more than one puppy in the uterus. Unfortunately, this is subjective and most veterinarians don’t get enough practice doing this (since most dogs and cats are spayed and not bred) to be consistently accurate.

Radiographs (X-rays) can be useful but are only accurate after about 45 days of pregnancy, once the fetal skeletons are ossified and can be detected with X-rays. Usually, by this time you can already tell from obvious abdominal enlargement that the dog is pregnant.

Abdominal ultrasound can be used with high accuracy 24 to 25 days after conception. It is the best test to determine if the puppies are alive, but it is not accurate for determining the correct number of puppies (or kittens.)

A commercial blood test that checks for the hormone relaxin is best used about one month after breeding. Work with your doctor to determine what tests may be most helpful for your particular situation.

I’ve heard that glucosamine and chondroitin might be removed from the market. I have used these supplements for the last two years for my collie Prince, who has bad hips. Why is this and when will it occur?

The FDA is evaluating glucosamine and chondroitin, as they are not generally recognized as safe in pets (though they are recognized as safe in people).

No one really knows what is going on at this point. These two supplements, used extensively in people and pets with arthritis, are among the most researched supplements.

Interestingly, the FDA does not seem interested in removing human supplements, only pet supplements. I have never seen any problems with them when used as directed, and did not uncover any in doing research for my book, “The Arthritis Solution for Dogs” (Prima, $14.95). At this time, they are still available and hopefully will not be removed from the marketplace.

Due to their high degree of safety, effectiveness and lower cost, I prefer them over conventional medical therapies for long-term control of pain and inflammation in dogs and cats with arthritis. I have found these joint supplements very effective and continue to recommend them.

Shawn P. Messonnier, author of the “Natural Health Bible for Dogs & Cats” (Prima, $24.95), is a veterinarian and pet-care advocate.