Two dogs with juvenile-onset skin diseases with involvement of extremities.

[junctional epidermolysis bullosa]

Two dogs of juvenile -onset skin diseases with involvement of extremities were examined by histopathological , immunohistochemical and ultrastructural analyses . Clinically , both cases showed alopecia and crusts on the face and extremities . Case 1 showed histopathology of dermo-epidermal separation . Ultrastructural analysis revealed that the clefts were recognized between hemidesmosomes and lamina densa . In case 2 , histopathology showed follicular atrophy , vacuolar degeneration at lower epidermis and masseter muscle degeneration , without remarkable ultrastructural abnormalities in basement membrane zone of the skin . Thus , the findings in case 1 were compatible to those in junctional epidermolysis bullosa , while those in case 2 were compatible to dermatomyositis -like disease . Combination of histopathological and ultrastructural analyses was useful to distinguish the diseases in two dogs .