Laryngeal Paralysis

Axonal degeneration and subsequent dysfunction of the recurrent laryngeal nerve -> atrophy and functional paralysis of the cricoarytenoid muscle which is the main abductor of the arytenoid cartilage -> inability to abduct arytenoid cartilage -> incomplete dilation of the larynx during inspiration and the flaccid arytenoid cartilage can be sucked into the laryngeal lumen during inspiration -> inspiratory dyspnoea
Caused by idiopathic neuronal degeneration
In Dogs
- Mainly large breeds eg: Labradors
- Usually bilateral disease
- Usually associated with other clinically apparent neurological or electromyographic defects
- May be caused by:
  - Hypothyroidism
  - Toxins - organophosphate toxicity, lead poisoning
  - Congenital abnormalities of the recurrent laryngeal nerve and brain stem - young age of onset
  - Secondary compression or inflammation of the recurrent laryngeal nerve

Test yourself with the Larynx Pathology Flashcards