Histopathological confirmation of polyneuropathy in 11 dogs with laryngeal paralysis.

Acquired laryngeal paralysis (LP) is an important cause of upper airway obstruction in dogs. We hypothesize that LP may be part of a generalized polyneuropathy complex. Electro-diagnostic studies were performed in six dogs, and histopathological studies of muscle and nerve biopsies were obtained from 11 dogs diagnosed with acquired LP. Abnormalities in electrodiagnostic procedures were consistent with a generalized polyneuropathy. Loss of large-caliber nerve fibers and axonal degeneration were identified in nerve biopsies, and neurogenic atrophy was observed in muscle specimens. Abnormalities in electrodiagnostic studies and histopathology provide evidence that LP may be part of a generalized polyneuropathy. Establishing a diagnosis of a more involved disease process is relevant for long-term prognosis.