Two Dogs with Juvenile-Onset Skin Diseases Involving Extremities

The study examined two dogs with juvenile-onset skin diseases affecting the extremities, both presenting with alopecia and crusts. Case 1 exhibited dermo-epidermal separation, with ultrastructural analysis showing clefts between hemidesmosomes and lamina densa, consistent with junctional epidermolysis bullosa. Case 2 showed follicular atrophy and vacuolar degeneration in the lower epidermis and masseter muscle, resembling a dermatomyositis-like disease, but without significant ultrastructural abnormalities in the skin's basement membrane zone. The combination of histopathological and ultrastructural analyses was effective in differentiating the diseases in the two dogs.