Changes

==Introduction==

==Introduction==

The larynx functions to regular airflow and voice production and to prevent inhalation of food. The arytenoid cartilages of the larynx abduct at each inspiration, and are controlled by the '''dorsal cricoarytenoid muscles'''. These are innervated by the '''recurrent laryngeal nerve'''.  

The [[Larynx - Anatomy & Physiology|larynx]] functions to regular airflow and voice production and to prevent inhalation of food. The arytenoid cartilages of the larynx abduct at each inspiration, and are controlled by the [[Larynx - Anatomy & Physiology#Intrinsic Musculature|

'''dorsal cricoarytenoid muscles''']]. These are innervated by the '''recurrent laryngeal nerve'''.  

Lesions to this nerve or to the muscle result in laryngeal paralysis, which can be unilateral or bilateral. The flaccid arytenoid cartilage is sucked into the laryngeal lumen during inspiration, leading to an '''inspiratory dyspnoea'''.

Lesions to this nerve or to the muscle result in laryngeal paralysis, which can be unilateral or bilateral. The flaccid arytenoid cartilage is sucked into the laryngeal lumen during inspiration, leading to an '''inspiratory dyspnoea'''.

Congenital and acquired forms have been recognised in dogs and cats:

Congenital and acquired forms have been recognised in dogs and cats:

<u>Congenital laryngeal paralysis</u>: reported in the Bouvier des Flandres, bull terriers, dalmatians, rottweilers and huskies.  

<u>Congenital laryngeal paralysis</u>: reported in the Bouvier des Flandres, Bull Terriers, Dalmatians, Rottweilers and Huskies.  

There is Wallerian degeneration of the recurrent laryngeal nerve and abnormalities of the nucleus ambiguus.

There is [[Wallerian Degeneration|Wallerian degeneration]] of the recurrent laryngeal nerve and abnormalities of the nucleus ambiguus.

The disease appears '''before 1 year of age''', earlier than in dogs with the acquired form.

The disease appears '''before 1 year of age''', earlier than in dogs with the acquired form.

<u>Acquired laryngeal paralysis</u>: most common in '''large breed dogs''' such as Labradors, St Bernards, Irish Setters over the age of 9. It has also been reported in cats. It occurs three times more commonly in males than in females.

<u>Acquired laryngeal paralysis</u>: most common in '''large breed dogs''' such as Labradors, St Bernards, Irish Setters over the age of 9. It has also been reported in cats. It occurs three times more commonly in males than in females.

The most common cause is '''idiopathic''', but other causes include: '''trauma''', '''neck surgery''' (thyroidectomies in cats), '''cranial mediastinal or neck mass''', '''hypothyroidism''' causing a polyneuropathy and polymyopathy.

The most common cause is '''idiopathic''', but other causes include: '''trauma''', '''neck surgery''' (thyroidectomies in cats), '''cranial mediastinal or neck mass''', '''[[hypothyroidism]]''' causing a polyneuropathy and polymyopathy.

==Clinical Signs==

==Clinical Signs==

Norsworthy, G. (2010) '''The Feline Patient''' ''Wiley-Blackwell''

Norsworthy, G. (2010) '''The Feline Patient''' ''Wiley-Blackwell''

[[Category:Larynx - Pathology]]

[[Category:Larynx - Pathology]]

[[Category:Respiratory System - Degenerative Pathology]]

[[Category:Respiratory System - Degenerative Pathology]]