Dear Dr. Fox: I read in today's paper about a dog with very sore gums. I am one of those rare people who is highly allergic to fluoride in water. I had very sore gums.

Even with teeth cleaning every three months, it didn't help. Apart from sore gums, I also had severe stomach cramps and explosive diarrhea for several years before it could be figured out what caused all of this.

Could some animals be allergic to fluoride in water, bringing on unexpected illness? Some bottled water also has fluoride. The only bottled water I've been able to drink without getting sick is Mountain Ice and reverse-osmosis water. It's worth checking out. -- B.B., Horace, N.D.

Dear B.B.: Your letter is important to all. You are particularly sensitive to fluoride, so one wonders what fluoride does to other people and animals who do not develop acute symptoms but may suffer the consequences of chronic exposure and toxicity.

Many countries have prohibited the addition of fluoride to treated municipal water. Chlorination -- an endocrine disrupter -- is hazardous enough.

Chronic fluoride exposure has been linked with many health problems from thyroid disease to bone cancer, especially in boys. Pets may be similarly affected. Fluoride accumulates in the bones and teeth. For more details, especially about high fluoride levels in some pet foods, visit www. twobitdog.com/DrFox.

Please give your animal companions quality spring water or purified water (not distilled). All municipal water authorities should cease and desist from adding fluoride (a byproduct of the agrichemical-fertilizer industry) to public water sources. Avoid pet foods that list "bone meal," "meat meal" and "chicken byproduct meal" as ingredients. They may contain a lot of round bone included during the "deboning" process.

Dear Dr. Fox: This is going to sound terribly disgusting, but I have a 20-pound, 11-year-old female cat who scooches her rump on the floor.

I have taken her to the vet, and there is nothing medically wrong with her. She is very furry, so I had her shaved in a lion cut, thinking this might help with feces that cling to her back fur. It made no difference.

I am at my wits' end. The vet had no other suggestions except for shaving. I have tried wiping her, but she gets extremely hostile. This hostility makes my male cat very angry and protective of me. The two cats then fight for the next 20 minutes.

I have tried a squirt gun. I have switched litters, looking for a better one. I have raised and lowered the litter levels in the box, as she likes to stand when going to the bathroom. I have rugs on the floor just for the purpose of addressing this issue, and I praise her when she uses one instead of regular carpeting.

Is there anything else I can try? I am starting to feel like a professional carpet cleaner. -- G.J.G., Falls Church, Va.

Dear G.J.G.: Disgusting or not, this is a stressful problem for all concerned. If your veterinarian ruled out anal-gland issues, you need to consider why your cat gets fecal material on her rear.

Try a much larger litter box so she can position herself easily and not get caught on an edge. Considering her age and the fact that she likes to stand while evacuating, the most likely problem is spinal arthritis. My book "The Healing Touch for Cats" may help, as well as a few sessions with a veterinary massage therapist, chiropractor or acupuncturist.

Many older cats have this evacuation problem associated with arthritis. You may also want to try a warm pad for her to lie on or use a heat lamp. Anti-inflammatory supplements like fish oil, turmeric and other beneficial products could make a world of difference. A little valerian could ease painful muscle spasms.