Laryngeal paralysis is a condition in which the opening to the larynx and trachea fails to open properly upon inspiration. This results in difficult inspiration especially as the need for oxygen increases with exercise and stress. Also because the respiratory system is one of the primary means of temperature regulation in the dog, high body temperatures result as the inspiratory effort increases. The condition can be seen in some breeds due to inherited factors (Bouvier) but is most commonly seen in older Labradors and other Retrievers greater than 10 year of age. The cause is considered idiopathic (with no known origin) and it is suspected that a neuropathy is present in the recurrent laryngeal nerves. Because there is a failure of these nerves to innervate the muscles of the arytenoid cartilages, they fail to open properly. Laryngeal function, i.e., opening of the larynx upon inspiration and closing during swallowing is an intrinsic function (involuntary). When these nerves begin to fail, the laryngeal opening is too narrow and inspiratory effort increases. The most prominent clinical manifestation of laryngeal paralysis is increased inspiratory airway sounds, usually increasing in intensity with excitement. Often the bark changes to more hoarse. It is common to see this condition most often during the warm, humid months. Generally in May, an increased number of patients surface with the condition. If this condition is allowed to go untreated, dog can develop such distress that they collapse and “pass out” from lack of oxygen. Often, their body temperature will rise to above 105 deg F. This can be a life threatening condition and requires emergency treatment.
Medically, Laryngeal Paralysis can be treated with low dose sedation and steroidal anti-inflammatory medication. Often, this treatment will only be successful for a short time and must be coupled with enforced restrictions. The treatment of choice is to surgically open the airway. Different techniques to permanently open the larynx have been tried over the years. The surgical procedure that appears to have the most success is what is known as a Left Cricoarytenoid Tieback.
Laryngeal Paralysis Surgery: Cricoarytenoid Tieback
In this procedure, usually performed from the left side, a surgical approach from the outside is made to the larynx to expose the thyroid, arytenoid and crico cartilages. The arytenoid cartilage is then “tied back” by passing 2 permanent sutures from the crico cartilage to the articular process of the arytenoid cartilage. The goal is to double or triple the laryngeal opening permanently. The procedure does not restore nerve function; instead, it simply creates a larger opening to afford better air flow. Rarely do both sides have to be tied back, in fact if the opening is made too large, the possibility of aspiration increases. The procedure has been shown to be very effective in restoring fairly normal airway function.
The most common complication to laryngeal surgery is aspiration; small feedings and amounts of water are recommended for the first 2 weeks. Often dogs will gag some on food and need to “re-eat” their food. Food should be kept at a moist but not runny consistency. Harnesses are recommended over the use of collars. Swimming must be observed very closely, as some dogs will splash so much that they increase the risk of aspiration and should not be allowed to swim.
When successful, laryngeal surgery for Laryngeal Paralysis can extend the quality of life for patients for years and is definitely recommended.