Inherited canine giant axonal neuropathy

Abstract

To date, a single case of canine giant axonal neuropathy (GAN) has been recorded. The present report describes the disease in 3 more dogs from the second litter produced by the parents of the original case. Regular clinical and electrophysiological examinations were carried out on all 11 dogs of the second litter. At 14--16 months of age, 3 dogs developed slight posterior ataxia which progressed to a severe lower motor neuron disturbance involving only the hind legs. During this period, each dog began to regurgitate food as a result of megaesophagus. From 12 months of age, there was a progressive reduction in the amplitude of the evoked muscle action potential. Biopsy of the tibial fascicular nerve at 16 months of age confirmed that all 3 dogs had GAN, with numerous swollen unmyelinated fibers and less frequent enlarged myelinated fibers containing accumulated neurofilaments.

Giant axonal neuropathy–like disease in an Alexandrine parrot (Psittacula eupatria)

“…Third, in other species, giant axonal neuropathy is typically (though not necessarily) associated with curly hair 10,21 ; no gross feather abnormalities were identified in this case. For these reasons, we believe that this condition is distinct from classical giant axonal neuropathy as reported in other species, and may represent a novel disease process.…”

“…3 Gigaxonin regulates neurofilament degradation by the ubiquitin–proteasome pathway, and defects in gigaxonin expression lead to accumulation of neurofilaments within axons. 16 The condition has been reported in humans and dogs as an inherited defect, 1,10 and has been induced experimentally in mice. 8 The disease manifests as early-onset motor and sensory neuropathy that progresses to central nervous system signs with seizures and eventual death.…”

Tetraparesis, Hemiparesis, and Ataxia

“…These disorders manifest as diffuse polyneuropathy that involve the distal appendicular musculature in the Alaskan Malamute, 560,561 Doberman pinscher (dancing Doberman disease), 562 German shepherd dog, 203,563,564 Great Dane, 565,566 Leonberger, 357,567 border collie, 568 and rottweiler. Both primary axonal degeneration and wallerian degeneration will cause neurogenic muscle atrophy later in the disease course.…”

Hereditary polyneuropathy in the Alaskan Malamute

“…Since the late 1970s various case reports about hereditary polyneuropathies in different canine breeds have been described such as the giant axonal neuropathy in German shepherds (11,12), the progressive axonopathy in Boxers (16), the hypomyelinating polyneuropathy in the Golden retriever (3), the laryngeal paralysispolyneuropathy complex in Bouviers de Flandre (24), young Dalmatians (6), young Rottweilers (17) and Siberian Huskies (21), the distal sensorimotor polyneuropathy in the Rottweiler (5), the hypertrophic neuropathy in the Tibetan terrier (8) and Mastiff (22), the sensory neuropathies in the English pointer (9,10) and Dachshund (13), and the distal symmetric polyneuropathy in the Great Dane (2). A recent review was provided by Granger (15).…”