Demyelinating Polyneuropathy in a Miniature Schnauzer: First Case Described in Spain

Introduction and case report:

Hereditary polyneuropathies are rare causes of neuromuscular weakness in companion animals.1 Clinical, electrodiagnostic and histopathological findings have been reported for several breed-related polyneuropathies.1-3 A presumptive hereditary demyelinating polyneuropathy has been described in Miniature Schnauzers in France, which resembles the demyelinating form of Charcot-Marie-Tooth disease.4 This report describes the first case of the disease in a Spanish Miniature Schnauzer.

A 4-month-old female entire Miniature Schnauzer was presented for evaluation of a four-week history of regurgitation, and loss of bark for two months. The owner also reported exercise intolerance compared to another female sibling from the same litter.

Neurological examination revealed normal mental status with pelvic limb ataxia, aphonic bark, and delayed postural reactions in the pelvic limbs with preserved segmental spinal reflexes, in the absence of spinal pain. Neurological localization was generalised lower motor neuron with main differential diagnoses of hereditary polyneuropathy, infectious/immune-mediated polyneuritis, and metabolic or inflammatory polymyopathies.

Initial investigations included haematology and comprehensive biochemistry, T4/TSH and serum CK activity, which were within reference ranges for a growing puppy. An ACTH stimulation test and electrolytes results were not consistent with hypoadrenocorticism. Conscious thoracic radiographs revealed dilation of the distal oesophagus compatible with megaoesophagus.  […]