Southeastern Cooperative Wildlife Disease Study, pp 212-215, 1988. The hematopoietic system. This dog had a history of chronic keratoconjunctivitis and generalized bilaterally symmetrical hair loss. In this case, there is a minimal superficial perivascular dermatitis with mild epidermal hyperplasia. Most sections have one or more anagen hair follicles, though many follicles are atrophied.
Some sections contain intrafollicular accumulations of inflammatory cells.
Arrector pili muscles are present, but not enlarged or vacuolated. The low baseline T4 level might indicate, but is not diagnostic for, hypothyroidism. There are no histologic changes to suggest hypothyroidism and it is unknown if the dog was on thyroid medication at the time of biopsy. Case 30-4 . There is hair follicle atrophy with clumping of melanin in one follicle accompanied by mild intrafollicular hyperkeratosis.