Dear Dr.Fox:

I have a Maltese female who is 3 years old. Ever since she was about 5 months old, she began chasing her tail. We thought at the time that it was cute, but soon came to realize it was the beginning of a problem. She will bite and chase her tail until almost all the hair on it is gone. Then the problem goes away -- until the hair starts to grow back and look nice, and it starts all over again.

It seems to me that it occurs most often after she has eaten, but it happens throughout the day. She whimpers at times while doing this and looks at me with an expression of "Please help me!" I don't know what to do. I try to distract her. I have used cortisone spray, which seems to help for a while but also makes her tail look wet all the time and not very attractive.

It's been suggested that she might have fleas, but I can tell you this isn't the case. She has eaten the same food ever since I got her at 7 weeks old -- Eukanuba and a small portion of chicken per day (she's a picky eater). Her groomer told me that she has dry hair and I should put mayonnaise on her before I bathe her once a week for an hour. This would be a big inconvenience; there must be something better to use. Could you please help my Misty?

L.F., MiamiThe obsessive-compulsive disorder (OCD) your dog exhibits can be extremely difficult to control, and severe mutilation of the tail necessitating amputation may be the sad end to the disorder if you cannot break the obsession.

Shake a tin can of old keys or nuts and bolts to distract her when she starts in on her tail. Try to re-motivate her with a fluffy toy on a string to chase.

Consider getting her a companion dog to help distract her. Bitter lemon (used to discourage infants from sucking their thumbs) on her tail -- not mayonnaise -- may also help.

For her dry skin, add a few drops of oil of primrose in her daily diet, which should also include some home-prepared food as well; my Web site (http://tedeboy.tripod.com/drmichaelwfox/id19.html) includes a basic recipe. There are also psychotropic drugs like Prozac to help animals overcome various OCDs, and this may be worth considering with your veterinarian's guidance. In addition, your vet should double-check Misty for skin allergies and impacted and inflamed anal glands.

Dear Dr. Fox:

You have repeatedly said in your column that mixed breeds have fewer inherited diseases than purebreds because of "hybrid vigor." I have spent close to $3,000 on my border collie/Australian sheepdog mix's hip dysplasia. So much for hybrid vigor!

S.L., Chevy Chase, Md.

Hybrid vigor is for real, but you get less vigor and more genetic defects in crossbreeds that come from breeds that share one or more inherited disorders. This is the case with the two breeds who created your dysplastic, expensive, but I am sure most wonderful and lovable canine companion.

Dear Dr. Fox:

With regard to home remedies for dogs: Several years ago, I had a beautiful (and expensive) female Shetland sheepdog puppy, for which I paid a handsome price. To my amazement, I noticed she was developing red mange around her mouth and on her paws.

A trip to the local veterinarian was in order. He gave me medication for the mange, but it only irritated the infected areas. He then suggested I take her to the Texas A&M veterinary school. There, they recommended that I put her to sleep!

I went back to my local vet and told him to come up with another solution -- I was not going to destroy my dog. He suggested aloe vera.

I called a fellow kennel club member who had aloe vera plants in her yard. She cut off a stalk, and I brought it home, wrapped it in damp paper and placed it in the refrigerator. That evening, I cut off a slice and rubbed my dog's affected areas with the center and held her still for 15 minutes. I repeated the treatment the next morning and for several days afterward. On the fifth day I noticed marked improvement, and a few days after that she was cured.

I hope this anecdote will aid people who want to help their dogs get over this awful affliction.

J.J.W., Houston

I want to note that this experience occurred "several years ago," because Texas A&M Veterinary College vets would not suggest that you have your dog euthanized today. Even so, her condition must have been severe for them to have made such a suggestion then.

I have heard of some remarkable results from treating animals for various skin problems using aloe vera extract, a purified form of which can also be taken internally for intestinal disorders. It evidently has soothing, anti-inflammatory properties and, hopefully, more clinical trials will be done and reported in veterinary literature to determine the effectiveness of aloe juice for treating skin conditions.

Michael Fox, author of many books on animal care, welfare and rights, is a veterinarian with doctoral degrees in medicine and animal behavior. Write to him in care of United Feature Syndicate, 200 Madison Ave., New York, N.Y. 10016. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

(c) 2004, United Feature Syndicate Inc.