Congenital hypotrichosis in a Simmental cross heifer.

Background: Congenital hypotrichosis is defined as a less than normal amount of hair, obvious at birth or in the first weeks of life. Causes are nongenetic or genetic.

Objectives: To describe the clinical presentation and histological features of a novel form of hypotrichosis in a heifer.

Animal: A 15-month-old Simmental cross-bred heifer was presented with a history of progressive hair loss, which started at four months of age and progressed to severe generalized hypotrichosis.

Methods And Materials: Anamnestic data, detailed clinical examination, haematological investigation, selected biochemistry profile, RT-PCR and ELISA for bovine viral diarrhoea virus did not suggest a cause for the hypotrichosis; skin samples were examined histologically.

Results: Histopathology of the skin showed a 50% reduction in the number of hair follicles and dysplastic hair follicles; these findings led to a diagnosis of congenital hypotrichosis. The distribution of the hair and some of the histopathological characteristics were potentially consistent with viable hypotrichosis. A marked reduction in follicle density, hypertrophy of sebaceous glands, hypoplasia of arrector pili muscles and moderate acanthosis with hyperkeratosis, which have not been described previously in viable hypotrichosis or other forms of congenital hypotrichosis, were also observed.

Conclusion And Clinical Significance: This case may represent a novel form of congenital hypotrichosis.