Deslorelin for the treatment of hair cycle arrest in intact male dogs

Background – Hair cycle arrest (alopecia X) refers to a canine alopecic condition of unknown pathogenesis, characterized by symmetrical, nonpruritic and noninflammatory alopecia that spares the head and distal extremi- ties. Hypothesis/Objectives – The objective of this study was prospectively to evaluate the efficacy of a 4.7 mg deslorelin implant in the treatment of intact male and neutered female dogs affected by hair cycle arrest. Animals – Ten Pomeranian dogs (eight intact males, two neutered females), four Italian spitz (three intact males, one neutered female), three miniature poodles (two intact males, one neutered female), two Siberian huskies (both intact males) and one intact male chow chow dog with confirmed hair cycle arrest were included in the study. Methods – Each dog was treated with a subcutaneous sterile implant containing 4.7 mg deslorelin. Responder dogs were re-implanted 6 months after the first implant in order to obtain a 1 year pharmacological exposure and 1 year of follow-up. Results – Hair regrowth was visible within 3 months in 12 of 16 intact male dogs (75%); no hair regrowth was noted in any neutered female dogs. The overall response to therapy was 60%. No adverse effects were noted. Conclusions and clinical importance – These findings suggest that deslorelin may be a treatment option for intact male dogs with idiopathic hair cycle arrest.