Ceroid lipofuscinosis in the Border Collie dog: Retinal lesions in an animal model of juvenile Batten disease

Ceroid lipofuscinosis, an inherited disorder of lipopigment accumulation, was identified in a group of Border Collie dogs. The dogs developed mental, motor, and visual signs between age 15 and 22 months and progressed rapidly to severe neurological disease. The principal signs were blindness and gait and behavioural abnormalities with progressive dementia. Lipopigment accumulation was severe in neurones and glial cells of the central nervous system and was present in some visceral cells. Inclusions with variable ultra‐structure were common in all cells of the retina, but the pigment accumulation did not damage the retinal architecture. The cytoplasmic inclusions were granular, sud‐anophilic, eosinophilic, and autofluorescent. Ultrastructural morphology varied, but fingerprint and curvilinear patterns predominated. The retinal lesions in the Border Collies were similar to those in English Setters with ceroid lipofuscinosis, but were much less severe than in juvenile human ceroid li‐pofuscinosis. This disorder bears a close resemblance to ceroid lipofuscinosis in English Setters and is another useful model for Batten's disease.