Inherited polyneuropathy in Leonbergers: laryngeal paralysis
3-year-old Leonberger with inspiratory stridor, a change in its bark and exercise intolerance. It walks with a high-stepping pelvic limb gait, with distal muscle atrophy and reduced withdrawal reflexes. Laryngoscopy confirms bilateral laryngeal paralysis.
What best explains the clinical picture?
chevron_right Show answer and explanation
A. Geriatric idiopathic laryngeal paralysis, limited to the larynx
The dog is young and also has signs of distal peripheral neuropathy in the limbs: the laryngeal paralysis is part of a generalised polyneuropathy.
B. Leonberger inherited polyneuropathy, progressive, for which genetic tests exist
Correct. It is an axonal polyneuropathy affecting the laryngeal nerves and the distal limb nerves. Genetic tests allow breeding advice, and laryngeal surgery should be approached with caution because of the risk of aspiration pneumonia.
C. Hypothyroidism, which will resolve with levothyroxine
The link between hypothyroidism and laryngeal paralysis is weak, and levothyroxine rarely resolves it. Moreover, the breed and age point to an inherited neuropathy.
D. Focal myasthenia gravis
Focal myasthenia can cause laryngeal weakness, but it does not cause distal muscle atrophy or reduced withdrawal reflexes.
lightbulb Key takeaway
Inherited laryngeal paralysis–polyneuropathy complexes occur in Leonbergers, Rottweilers, Dalmatians and Alaskan Malamutes, among other breeds. In geriatric Labradors, laryngeal paralysis is usually also part of a slowly progressive polyneuropathy (GOLPP) that affects the oesophagus. Diagnosis relies on electromyography, nerve conduction studies and nerve biopsy.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.