Retrievers are one of the breeds in which laryngeal paralysis occurs more commonly
What is laryngeal paralysis?
Laryngeal paralysis is a condition where the larynx (voice box) fails to open the vocal cords when breathing in. This makes it difficult to breathe, particularly when active, which results in a spectrum of symptoms from noisy breathing and reduced ability to exercise through to life threatening obstruction of breathing in severe cases. The condition is most commonly seen in middle aged to older dogs of medium to large breeds such as Labradors, Retrievers, Weimeraners and Great Danes. It is occasionally seen in young dogs of certain breeds and small breeds but it is uncommon in these cases.
What are the symptoms of laryngeal paralysis in dogs?
Common symptoms are:
- Increased noise when breathing. This is typically a raspy noise and loudest on breathing in. The noise increases with excitement and activity
- Reduced ability to exercise
- Collapse and sometimes cyanosis (blue lips and tongue)
- Change in bark
- Cough often retching in nature
Some patients may also have:
- Difficulty swallowing food and or water
- Weakness in the hind legs
Laryngeal paralysis is usually a progressive condition with a gradual onset and then worsening over months to years.
What causes laryngeal paralysis in dogs?
In the majority of dogs the condition results from a failure of the nerves which control the larynx to function normally. The exact cause of this nerve dysfunction is unknown but it is considered a condition of ageing. The laryngeal nerves are the first affected in the body because they are the longest, but some dogs will gradually develop symptoms of other nerve dysfunction including back leg weakness and swallowing problems.
This diagram shows how the larynx cannot open properly in cases of laryngeal paralysis
In occasional cases the following can result in laryngeal paralysis: trauma to the neck, nerve damage during surgery in the neck, tumours of the neck and chest, poorly controlled under-active thyroid, specific neurological conditions of the nerves.
How is laryngeal paralysis confirmed?
The typical symptoms and breed of dog are often highly suggestive of laryngeal paralysis; however examination of the larynx under a light anaesthetic is required to confirm the diagnosis. At the same time blood tests to check for other diseases and a chest x ray to rule out complicating factors such as tumours and pneumonia are performed.
How is laryngeal paralysis treated?
Laryngeal paralysis cannot be treated with medication and is best treated with surgery. Symptoms can be reduced by using a harness and not exposing the animal to hot and humid conditions. However care must be taken as these patients can suddenly deteriorate and develop life threatening obstruction to breathing. This deterioration can sometimes be sudden and without warning.
This photograph shows the larynx of a dog following laryngeal tieback surgery to treat laryngeal paralysis. One of the vocal folds is held in a permanently open position to help the dog to breathe more easily
Surgery provides a highly effective treatment for laryngeal paralysis. The procedure performed is known as a ‘laryngeal tieback’ or an ‘arytenoid lateralisation’. This surgery permanently holds one of the vocal folds in an open position, making it easier to breathe. The outcome with this surgery is very good with 90-95% of dogs having significantly improved ability to breathe and exercise. The surgery also removes the risk of life threatening airway obstruction. This is a technically demanding surgery and should only be performed by a surgeon experienced in the procedure.
Minor complications of surgery include:
- Seroma formation (tissue fluid accumulation at the surgical site)
- Increased coughing and gagging often associated with eating and drinking
Serious complications are uncommon but occur in approximately 5-10% of cases. These include:
- Airway swelling and obstruction
- Suture (stitch) failure or cartilage fracture resulting in failure of the surgery
- Aspiration pneumonia (inhaling food or fluid into the lungs resulting in serious lung infection)
Aspiration pneumonia is a lifelong risk following surgery. Certain patients are at higher risk of this complication, particularly those with difficulty swallowing before surgery. If identified as high risk, proceeding with surgery should be carefully considered in these patients. If identified early, pneumonia can be treated successfully in most patients with antibiotics. However it can prove fatal in up to 20% of cases. Early signs are dullness and loss of appetite, quickly progressing to rapid breathing and a cough.
If your pet has had laryngeal tieback surgery and you suspect pneumonia you should seek urgent veterinary advice.
How do I manage my pet after surgery?
- Use a harness and never use neck collars for restraint or exercise
- Take care in hot humid conditions. Even following surgery these patients cannot cope normally with these conditions
- Feed firm tinned food to reduce the risk of aspiration pneumonia
- Give only water to drink. Avoid gravies and milk which increase the risk of pneumonia
- Monitor carefully for the early signs of pneumonia