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RESPIRATORY -

LARYNGEAL PARALYSIS

Laryngeal Paralysis is most commonly diagnosed in large breed dogs over the age of 10 years.  Paralysis is due to degeneration of the recurrent laryngeal nerve, one of the longest nerves in the body.  Paralysis of the nerve means that the cartilages at the back of the throat (larynx) do not actively open the airway when the patient breaths in.  Instead of opening up, the larynx collapses inwards and closes.  Patients present with difficulty breathing during inhalation (harsh, raspy, stridor), a change of bark (soft, harsh bark), and in severe cases turn blue (cyanosis) and collapse.

Surgery involves artificially tying opening one side of the larynx using sutures (laryngeal tie-back) so the patient is able to breath in, and not have the larynx close.  The goal of surgery is to open the airway and minmise the risk of future life threatening breathing episodes.  Some respiratory noise will remain following surgery, in upto 30% of cases, and a return to full exercise tolerance and heat tolerance may not be complete. The outcome as determined by clients post-operatively is good in over 90% of cases.

Complications may occur either in the immediate post-surgery period or at some stage in the future.  Early complications are related to inflammation and swelling, and may require a temporary hole to be made in the base of the neck (tracheostomy) until the swelling subsides and the patient is able to breath without issues. Infection rates are low, generally 2-4%, and usually managed with oral antibiotics.  Later complications observed, are breakages of the sutures or breakage of the cartilages the sutures are in, either due to excessive barking and activity or old age degenerative changes.  Should suture breakage occur then a second surgery to tie-back the other laryngeal cartilage may be required to open the airway again.  

 

Another serious, late, complication which may occur is inhalation of food into the lungs (aspiration pnuemonia) due to the larynx having to be artificially and permanently tied open.  The risk of aspiration pnuemonia is approximately 15%, and should be monitored for closely at all times following surgery. Aspiration pnuemonia is life threatening and should be identified early and treated pro-actively with hospitalisartion and intravenous antibiotics.