A Bulldog With Focal Alopecia November 1999 Veterinary Medicine

A Bulldog With Focal Alopecia November 1999 Veterinary Medicine: "Seasonal affective disorder can be culprit for canine hair loss

Coming off of a long, dark winter as we are in the Midwest, we're confronted with a unique disease seen in certain breeds of dogs. Light responsive alopecia or seasonal flank alopecia is most often seen at this time of the year. It is not well understood but is thought to be from lack of sunlight
exposure to the pineal gland. The pineal gland is located at the base of the brain and is the gland responsible for telling bears to hibernate and perhaps telling us to crawl into bed early during these long winters, eat fatty foods, and in general, not have much energy.

These changes are not recognized in dogs but physical changes such as trun-cal alopecia and hyperpig-mentation are evident Light responsive alopecia is logically more common in those areas of the country with dark winters such as the Midwest, the Plains states, parts of New England and Canada. Studies of seasonal affective disorder in humans show an incidence of 2 percent in Florida vs. 10 percent in New Hampshire. When seen in other parts of the country or at other times of the year it maybe evident that affected dogs are house bound during the daylight hours for a prolonged period of time. For example, the owner leaves before dawn and arrives home after sunset so the dog is exposed to virtually no natural sunlight. It is not known whether the disease is comparable between humans and animals but what is certain is that a photo period plays a role in both."