Congenital and Inherited Skin Disorders

Lavender foal syndrome (LFS) is a lethal inherited disease primarily seen in foals with Egyptian Arabian breeding and is inherited in an autosomal recessive pattern. LFS diagnosis is based on signalment and characteristic coat color dilution, with definitive diagnosis made via DNA testing to demonstrate presence of mutated MYO5A gene. Subepidermal bullous disease was identified in a 1-day-old Appaloosa foal that presented with vesicles and bullae over the oral, anal, and genital mucosal surfaces. The foal was treated with ceftiofur sodium therapy for 1 week. Hypersensitivity to insect bites is the most common allergic skin disease of the horse, commonly caused by hypersensitivity to the salivary antigens of the Culicoides sp. The management of insect-bite hypersensitivity includes insect control and pharmaceutical control of pruritus. Lymphoma has been reported in foals and aborted fetuses. These animals may have cutaneous and visceral involvement of multiple sites and organs.