A review of mitochondrial disease in dogs

Mitochondria are maternally inherited cellular organelles located in the cytoplasm of most eukaryotic cells. Mitochondrial diseases are a type of metabolic disorder, involving the respiratory chain under the control of both the mitochondrial DNA and nuclear DNA. In dogs, mitochondriopathies are considered rare, with few clinical syndromes having had their structural, biochemical and genetic basis identified. In this review, the basis for suspecting a mitochondrial disease clinically is summarised, with particular focus on mitochondrial encephalopathies, encephalomyelopathies and neuropathies. Recognisable confirmed mitochondriopathies including spongiform leukoencephalomyelopathy, Alaskan Husky encephalopathy, Leigh-like subacute necrotising encephalopathy and sensory ataxic neuropathy in the Golden Retriever are described in detail, alongside previously reported individual cases of presumptive mitochondriopathies of unknown origin. Genetic mutations reported in the literature are reviewed. A clear classification for mitochondrial diseases in veterinary medicine is lacking, and this review is the first to address this class of diseases specifically in dogs.