A 29-month-old female Alaskan husky was presented recumbent, tetraparetic a
nd in a state of dementia, with blindness and cranial nerve deficits. The d
og's progress was followed for over two months, as the signs resolved to a
non-progressive mild hypermetria with slight proprioceptive ataxia, a dimin
ished menace response and inability to prehend food. Magnetic resonance ima
ging (MRI) revealed bilateral cavitation extending from the thalamus to the
medulla, with less pronounced degenerative lesions in the caudate nucleus,
putamen and claustrum. Cerebrospinal fluid lactate and pyruvate concentrat
ions were in their normal ranges. Necropsy and histological examination con
firmed the MRI findings as well as neuronal degeneration of the cerebellar
cortex in the vermis and degenerative changes in the neocortex at the depth
s of the cerebral sulci. In view of the similarity of lesions to subacute n
ecrotising encephalomyelopathy, known as Leigh's disease in humans, a tenta
tive diagnosis of a mitochondrial encephalopathy was made.