Uveodermatologic Syndrome in a Laboratory Beagle Dog: Histological and Immunohistochemical Features

This brief communication details the clinical, macroscopic, histological, and immunohistochemical features of a spontaneous case of uveodermatologic syndrome (UDS) in a laboratory beagle dog. A bilateral and symmetrical panuveitis, rich in macrophages and T lymphocytes, with distinctive extracellular clumped or phagocytised melanin pigment granules, and Dalen-Fuchs nodules was diagnosed following occurrence of ocular symptoms and subsequent blindness in a female peripubertal 9.5-month-old beagle dog. Although no macroscopic lesions were visible in the skin, microscopic examination revealed a histiocytic and lymphocytic lichenoid dermatitis with pigmentary incontinence. UDS has not been described as a background finding in laboratory beagle dogs before, although it is a well-known immune-mediated disease in certain canine breeds. Knowledge that UDS can occur in laboratory beagle dogs involved in preclinical studies, especially ocular studies, is essential for toxicologic pathologists.