Progressive myelopathy and neuropathy in New Zealand Huntaway dogs

To investigate the nature and cause of a progressive ataxia in three 20-month-old Huntaway dogs that were litter mates.

Affected dogs were examined before they were humanely killed and submitted to necropsy. Selected formalin-fixed tissues were examined by light and electron microscopy.

The lesions were those of axon and myelin degeneration within sensory, proprioceptive and motor tracts of the spinal cord and to a lesser degree some peripheral nerves.

A progressive myelopathy and neuropathy, tentatively described as a central-peripheral distal axonopathy, was present in all 3 dogs. The cause was not determined but was likely to be either genetic or nutritional.

In the early stages of this disease, careful examination may be necessary to distinguish the signs of ataxia from orthopaedic disease such as hip dysplasia. Affected animals are unlikely to be of use as working dogs.