Laryngeal Paralysis in Dogs
Laryngeal paralysis is a medical condition affecting dogs, where the muscles in the larynx are no longer able to move the arytenoid cartilages open and closed. The larynx is part of the upper airway. When the laryngeal muscles are no longer working properly, the arytenoid cartilages remain open, leading to abnormal breathing sounds and increases the risk of aspiration of food and liquids into the lungs. One or both sides of the larynx can be affected.
Causes of Laryngeal Paralysis in Dogs
Laryngeal paralysis can be a genetic condition, especially in Siberian Huskies, Bull Terriers, Bouvier de Flanders, Great Pyrenees, and Dalmatians. Clinical symptoms tend to present as puppies under a year of age.
There is also a non-genetic form of laryngeal paralysis, termed acquired laryngeal paralysis. It’s thought most of these cases develop from a generalized neuromuscular disease that can affect other areas of the body over time. This is most common in older or geriatric dogs. Labrador Retrievers are commonly affected and so are other large and giant breeds, while smaller breeds are less commonly affected.
Laryngeal paralysis can also occur due to direct trauma to the neck and nerves that innervate the larynx. Surgery in the upper part of the neck, tumor formation in the upper neck region, or fight wounds in the area can all damage the nerves and lead to laryngeal paralysis.
Many dogs with laryngeal paralysis also have hypothyroidism. Unfortunately, treating the dog’s hypothyroidism does not seem to improve or reverse the laryngeal paralysis. Megaesophagus is another disease often found in dogs with laryngeal paralysis.
Common Symptoms of Dogs with Laryngeal Paralysis
The most common symptom is a change in the sound of the bark/voice or a change in the sounds of inspiration. This is called stridor and results from a change in vibration and air movement through the larynx because it cannot fully open and close. This symptom will get worse with increased activity, so it will sound louder after running and playing or if your dog is getting too hot.
Other signs include:
- Respiratory distress
- Trouble inhaling
- Change to the sound of the bark
- Blue discoloration of tongue or gums (cyanosis)
- Coughing or gagging when eating or drinking
- Difficulty apprehending food and chewing
- Weakness in the limbs, especially with geriatric onset laryngeal paralysis
- Regurgitation of undigested food
- A recurrent or single episode of aspiration pneumonia
How is laryngeal paralysis diagnosed in dogs?
A complete physical exam is the first step. Your dog may need to be jogged around the clinic to increase breathing rate and effort in order to hear the changes in sound when breathing. After the physical exam, the next step is often lightly sedating your dog to be able to actually visualize the larynx. After being sedated lightly, a drug to stimulate respiration is often given to observe the movement of the arytenoid cartilages and see if they’re able to open and close correctly and if one or both sides are affected.
Ultrasound of the neck/larynx area can also evaluate the movement ability of the muscles in the larynx. This is often done by an experienced radiologist or ultrasonographer.
Radiographs of the chest are often recommended to screen for signs of aspiration pneumonia and also evaluate the esophagus. Many dogs with laryngeal paralysis also have megaesophagus.
How is laryngeal paralysis treated?
Mild cases with no history of respiratory distress or difficulty breathing during exercise, stress, or hot weather can likely just be monitored. Using a harness instead of a collar is ideal to prevent excess pressure on your dog’s upper airway. It’s safest to avoid exercise in warm to hot weather as this can lead to airway swelling and breathing difficulty.
If your dog gets stressed, such as separation anxiety or storm phobias, be sure to discuss sedatives or tranquilizer medications with your vet. Using slow feeders, canned or moistened kibble, and slowing down water ingestion can also help reduce coughing and aspiration pneumonia.
In severe cases, surgery is needed. This is not a cure! The goal of the surgery is to improve the size of the airway opening to reduce respiratory distress and stridor. The most common surgical procedure is called Arytenoid Lateralization Laryngoplasty, commonly called “tie-back surgery”. This can be done on one or both sides. Since the airway is now permanently secured in an open position to facilitate breathing, it means your dog will be at a higher risk for aspiration pneumonia.
Acupuncture has been reported to help manage clinical symptoms, so discuss this with your vet.
Finally, there is a drug called Doxepin that may help your dog. This is a tricyclic antidepressant. There are no published studies on using this drug for laryngeal paralysis, but anecdotal reports seem to suggest it can really help some dogs. This is an off-label use for the drug and you may need to sign a waiver or consent form if you and your vet decide to try this treatment option.
Please click on the link for a YouTube video of the sounds dogs make when breathing with laryngeal paralysis/stridor:
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