Fall is a good time to examine your pet's coat and skin for any external parasite "hitchhikers," such as fleas, lice, mites or ticks, picked up over the summer. Your pet may have become the host for one of these pests through contact with a "carrier" animal or by roaming through the pest's natural outdoor habitat.

Excessive scratching, hair loss, inflammation of the skin, a foul odor, or twitching of the ears are all indications of skin parasites. A careful examination of your pet around the neck area, between the toes, in and around the ears, and in the folds between the legs and body may confirm your suspicious.

If you notice any symptoms of parasites, call your veterinarian. Do not attempt home remedies. Insecticides are toxic products that could harm you and your pet if used improperly. Treatments vary for type of pest and pet species. Let your veterinarian determine the treatment and prevention.

Many external parasites feed and multiply on your pet and then shed eggs within and outside your home. Since the key to controlling these pests is breaking their life cycles, you will need to attack them from many directions.

Your veterinarian may recommend either bathing or dipping your pet in a special preparation. In the case of ear mites, a professional procedure may be required. You may need to "depest" your pet's living quarters, including the bedding, furniture and floor. Clean hard surfaces with a good household disinfectant. Be sure to empty the vacuum cleaner bag immediately after vacuuming to avoid creating a new nesting place for the pest. Your veterinarian may recommend sprays or foggers to stop eggs from hatching.

It may be necessary during warm weather to spray the yard where your pet roams. Common house and garden types of insecticides may do the job. However, keep your pet away from the area until all danger of contamination in past. Pets habitually lick their paws and fur to clean themselves and can very easily become poisoned.

The writers are Dr. Steven B. Holzman, Dr. William R. Haagenson and Dr. Kathleen Tapley. They are associated with the Nassau-Suffolk Veterinary Hospital of Farmingdale.