Seasonal Flank Alopecia

Before

After

This 9-year-old Basset Hound slowly developed hair loss (alopecia) on each side of the body.  The severity of hair loss had waxed and waned for the last 5 years.  Skin biopsy confirmed cyclic flank alopecia.  Hair loss with this disease usually occurs in the winter when melatonin levels should be the highest.  Hair may grow back partially in the summer, only to be lost again the following winter.  This disease is only seen in northern latitudes, where the duration of daylight is much shorter in the winter than in the summer.  The Basset Hound was treated by surgically placing an implant under the skin that slowly released melatonin.  Hair growth was marked within 2 months.  Melatonin implants were first used in the fur industry to artificially induce luxuriant winter pelts in fox and mink.