Résumé : Objectives: To characterise clinical, electrophysiological and histopathological findings. To analyse pedigree information in six young related Pyrenean mountain dogs with laryngeal paralysis-polyneuropathy complex (LP-PNC). Methods: A retrospective study of clinical records and pedigrees of six young related Pyrenean mountain dogs with LP-PNC was carried out. Results: All dogs were presented with laryngeal paralysis and concurrent megaoesophagus. Electrodiagnostic testing was performed in three dogs and showed electrophysiological abnormalities in the distal appendicular muscles. Histopathological findings of peripheral nerve samples were dominated by distal axonal degeneration. Clinical, electrophysiological and histopathological findings were supportive of a diagnosis of degenerative, sensorimotor LP-PNC, similar to that reported in young dalmatians and rottweilers. All dogs died or were euthanased by two years of age. An autosomal recessive mode of inheritance was suspected based on pedigree analysis. Clinical Significance: Congenital LP-PNC should be suspected in any young dog presenting with laryngeal dysfunction and other concurrent neurological abnormalities. The prognosis is usually poor. © 2006 British Small Animal Veterinary Association.