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LARYNGEAL PARALYSIS by Dan Reimer DVM SURGICAL OPTIONS
LARYNGEAL PARALYSISClinical signs can really vary based on the severity of each dog's problem. They may just have a voice change in the very early stages, which may progress over time to excessive panting, especially during any exercise or excitement, or even just coughing. These are common signs with other throat infections and some relatively minor problems. This can progress well beyond this to stridor (a harsh, high pitched roaring sound heard mainly on inspiration). When this sign starts to develop, most people realize something real is happening. Their dogs may go further to develop exercise intolerance, collapse, and cyanosis.
The condition is caused by some condition affecting the recurrent laryngeal nerves leading to a loss of their function. These nerves innervate the larynx allowing it to open up (abduct) when a dog is taking a breath. When the condition occurs, a dog's airway is narrower than it should be, which is especially hard on an animal when it needs more air (like during exercise or excitement). The body needs more air, but it can't get it, so an animal pants and breathes even harder. The larynx may have a great deal of swelling associated with this, which even further narrows the airway. If it severe enough, the animal can pass out from lack of oxygen. We are not sure exactly what causes the nerves to loose function, but some of the causes include hypothyroidism, brain lesions (including tumors, inflammation etc.), and polyneuropathies. In most cases a cause is never found.
Medical treatments are only palliative and all are aimed at reducing swelling, or just calming down the dog. Rest, corticosteroids, antihistamines, sedatives may all have beneficial effects. If the condition continues to get worse, to the point where it becomes debilitating, surgery is the next step. The goal of surgery is simple: open the airway. There are various different types of procedures done to "tie back" the arytenoid cartilage or open the airway. Individuals seem to respond differently to the surgery. In some cases they do very well post-operatively. Unfortunately, some dogs are very prone to inhalation pneumonia afterwards, as any surgery in this area may affect the swallowing mechanism.
In short, this can be a truly frustrating and disheartening condition. Our goal is always to keep the dogs as comfortable as possible, and in most cases surgery becomes the only way to achieve that, but even that can have serious complications.
It is very common for dogs with LP to have to undergo surgery in order to alleviate the problem. Here is some information that I have compiled regarding the surgical options.
There are two basic surgical approaches commonly done for Laryngeal Paralysis: Extralaryngeal (from the outside of the throat) and Intralaryngeal (usually through the mouth).
The most common technique seems to be the Extralaryngeal technique which involves cutting through the neck, close to the jugular, isolating the laryngeal "folds" and stitching one or both of the folds open. It seems to be more common to tie just one of the folds back as it reduces post operative complications. These complications can include swelling and hemorrhage on the short term and on a long term basis the aspiration of food or water that could lead to aspiration pneumonia. Most dogs will have a tendency toward aspiration (especially of water) for a short time following surgery, but they will become more adept at drinking as time passes and have fewer aspiration episodes. Several small meals instead of one or two large ones is recommended so that the dog can learn to eat without severe side effects. The advantages of the tieback are that the dog does not build up scar tissue in the larynx which could cause severe complications later on and it is a far more permanent solution to the problem than are other procedures.
The Intralaryngeal technique includes a resection of the vocal folds or a resection of one or both sides of the vocal laryngeal folds. This procedure is often done through the mouth. Where this is a less invasive surgery, complications can arise from scar tissue forming in the larynx and this technique often involves performing a tracheotomy which will compensate for the swelling and possible hemorrhage that can occur following surgery. Also this technique is not as permanent as is the tieback surgery.
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