A dermatosis resembling juvenile cellulitis in an adult dog.

A two-year-old, female Lhasa apso presented with an acute onset of fever, anorexia, lethargy, prescapular and mandibular lymphadenopathy, otitis externa, and a dermatitis involving the perioral and auricular skin. Histopathological examination of affected skin and a mandibular lymph node was diagnostic for juvenile cellulitis. Extensive hematological, serological, urine, skin, and fecal testing together with special staining, immunofluorescence, and electron microscopic examination of skin and lymph node biopsies failed to reveal an underlying etiology. After 15 weeks the condition resolved completely. This represents the first adult case of a dermatosis fitting the clinical, histological, and clinicopathological description ascribed to juvenile cellulitis.