THE PET HEALTH LIBRARY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

What is This?

Seasonal flank alopecia is exactly what it sounds like, though it helps to know that alopecia means hair loss. With seasonal flank alopecia, a dog loses hair in the flank area on a seasonal basis. Different dogs seem to choose different seasons to lose their hair (fall and spring are popular) and when the season changes the hair generally grows back. Sometimes a dog will skip a season only to lose hair again the next year. Most affected dogs are Boxers, Airedales, and English bulldogs, though numerous other breeds have been affected.

The hair loss is generally confined to the flanks (area just ahead of the rear legs) though sometimes the bridge of the nose is involved. The skin typically is darkly pigmented in the areas of hair loss. Both flanks are generally affected symmetrically and sometimes there is skin infection in the balding areas. Sometimes the hair re-grows in a different color than the original hair. Some dogs never re-grow their hair.

Why Does this Happen?

At this time no one knows why this occurs. It is felt to be a hormonal problem disrupting hair follicles.

Is there Treatment?

Melatonin, a natural biochemical that is important in the regulation of circadian (daily) rhythms, has been used successfully in many patients. In the U.S. this product is available over the counter as a dietary supplement. A more effective method seems to involve the use of melatonin implants under the skin, but they are not available in the U.S. Melatonin is sometimes used as a sleep aid in people and the only known side effect is drowsiness. Dosing regimens must be obtained from the veterinarian treating the dog in question.

Date Published: 8/6/2009 10:25:00 AM