Clinical and pathological observations in English cocker spaniels with primary metabolic vitamin E deficiency and retinal pigment epithelial dystrophy.

Fifteen English cocker spaniels with confirmed vitamin E deficiency were examined physically, ophthalmologically and neurologically. Eleven of them had clinical signs of neurological dysfunction which included ataxia, proprioceptive deficits, abnormal spinal reflexes and muscle weakness. In the two dogs examined histopathologically there was central neuronal fibre degeneration with prominent neuroaxonal dystrophy, particularly within the sensory relay nuclei of the brainstem, and one of the dogs had severe intestinal lipofuscinosis.