in animals is a condition in which the nerves and muscles that move one or both arytenoid cartilages of the larynx cease to function, and instead of opening during vigorous inspiration and closing during swallowing, the arytenoids hang loosely in a somewhat neutral position.
Laryngeal paralysis is a condition that most often affects older, larger breeds of dogs, the Retriever breeds, Rottweilers and Setters are commonly seen. Clinical signs include exercise intolerance, noisy breathing (stridor), increased inspiratory efforts and bluish coloration of the tongue and gums (cyanosis). In extreme cases anxiety, heroic attempts to breathe and collapse can occur. The cause of this condition is a progressive neuromuscular disease that affects a single muscle on each side of the larynx. The condition is often seen in conjunction with hypothyroidism which may be caused by the same degenerative process. As the condition develops, signs include anxiety and visible expansion of the chest when the dog is trying to breathe heavily.
In normal dogs, the trachea is protected during eating and drinking by the epiglottis and arytenoids cartilages. During inhalation the arytenoid cartilages are actively are pulled to the side of the airway, allowing air to pass into the trachea/lungs. Dogs that suffer from laryngeal paralysis, lose arytenoid function which causes these cartilage curtains to be pulled into the airway making air passage into the lungs more difficult. Over time the turbulent airflow over the arytenoids causes them to thicken and swell, resulting in progressive loss of airway function. As the affected dogs struggle to obtain adequate breathing function, the increased negative pressure causes further collapse and swelling of the airway. This results in oxygen starvation (hypoxia) over heating (hyperthermia) and can lead to death if untreated.
As the dog works harder to pant, it actually causes the cartilages to block the trachea more, resulting in less oxygen intake than it could otherwise be getting. When the dog cannot take in enough oxygen, it becomes anxious and tries to breathe even harder, compounding the problem.
Emergency treatment of this condition includes the administration of steroids to reduce airway swelling, the use of sedatives to decrease the respiratory efforts and may necessitate the placement of an endotracheal tube or an emergency tracheotomy.
- Occurs most often in large breeds such as Labrador Retrievers, Golden Retrievers, Saint Bernards, and Siberian Huskies
- Symptoms may include:
- Voice change, may sound hoarse
- Noise while inhaling and exhaling
- Symptoms worsen in hot, humid weather or after exercise
The recommended surgical treatment for laryngeal paralysis is Arytenoid tie-back/lateralization procedure. The goal of the procedure is to increase the size of the functional airway to allow adequate ventilation. 1 or 2 permanent sutures are placed through the arytenoid and cricoid cartilages, mimicking the normal muscle function, and opening one arytenoid cartilage (usually the left).
The procedure has a high success rate in that 90-95% of the dogs have adequate respiratory abilities to function as pets. It is not recommended that these dogs swim or attempt to return to athletic function after surgery. Complications are rare but can include failure of the suture to maintain adequate lateralization and fluid accumulation at the incision site. Long term treated dogs can have low grade bouts of aspiration pneumonia that can successfully be treated at home with antibiotics. Respiratory sounds will continue to be harsh, and some coughing when eating or drinking should be expected. In addition treated dogs should not be kept outside in hot weather or left unattended in a vehicle. Leash walks are recommended and the use of a harness will prevent pressure on the airway.
After Care Instructions:
Following this procedure, it is common to see coughing after eating and drinking, which usually tapers off and ultimately stops, as well as the loss of voice, which in many cases of laryngeal paralysis has already occurred. Food and water will need to be elevated initially after the procedure to prevent regurgitation and a harness will need to be used in place of a leash indefinitely.
- For the first 24 hours following surgery, the chance of airway edema is present, therefore your pet will need to stay overnight one night and will need to be picked up during regular business hours the day after surgery. There will be staff overnight to monitor your animal.
- When you get your pet home, place your pet in a cool/warm (season dependent), quiet and dark room. If you leave your pet alone, he/she will sleep and be comfortable. You can increase your pet’s anxiety by doting. Your pet will have adequate medication for pain so you do not need to worry about discomfort.
- Cephalexin or another antibiotic may be dispensed. Please give according to label directions until gone.
- Prednisone may be dispensed. Please give according to label directions until gone.
Food & Water:
- When you get your pet home, offer him/her a small amount of water. If your pet drinks it and does not vomit, then offer twice the original amount.
- Two hours later if no vomiting has occurred, offer ¼ of the amount of food in a normal meal.
- If your pet eats and no vomiting occurs in a 2-hour time period, then you may resume normal feeding(s).
- Please call Dr. Dew’s or your veterinarian’s office if your pet does not drink within the first 6 hours of being home or if vomiting occurs.
Your pet should be rechecked by Dr. Dew 7-10 days following surgery. Please call (866) 838-4282 to schedule this appointment.
- Use of a harness rather than a collar, permanently, would help prevent stress on the neck.
- Your pet should be restricted to leash activity for one month.
- Your pet should be restricted to short leash walks in the cool of the morning and evening.
- At no time should your pet be left unattended in the yard or in a vehicle. Your pet will be intolerant of hot, humid conditions for the remainder of his/her life.
Dogs with an Arytenoid Tieback will experience an occasional bout of aspiration pneumonia. When this occurs, your pet will become lethargic and stop eating. Your veterinarian will confirm the diagnosis with a chest radiograph and antibiotics should resolve the problem.