The pathology of a sensory neuropathy affecting Long Haired Dachshund dogs

Summary

The microscopical findings in a sensory neuropathy affecting Long Haired Dachshund dogs are described. This disorder, which may have a genetic basis, results in loss of proprioception, touch and sense and reduction or loss of nociception and urinary control. In the distal cutaneous nerves, there was a severe loss of large myelinated fibers but unmyelinated fiber density was not reduced. Many of the remaining myelinated fibers contained accumulations of axonal organelles and teased fibers showed that some were degenerating whilst others had successive areas of paranodal demyelination. There was marked pathology of unmyelinated fibers with proliferation of tubulo-vesicular profiles resulting in the formation of stacks or lamellar arrays and darkening of the axoplasm. There were numerous regenerating unmyelinated axons. In the spinal cord, axonal degeneration was scen in the distal portion of the dorsal columns.

The clinical signs in this distal axonopathy were therefore compatible with the widespread sensory nerve pathology which was found. It is concluded that this neuropathy resulted from progressive nerve degeneration and comparisons between this neuropathy and other sensory neuropathies in animals and man are made.