The larynx, which is the opening through which outside air flows into a dog’s lungs, allows for vocalization and prevents food inhalation (aspiration) — both of which are important functions. Paralysis of the larynx, otherwise known as laryngeal paralysis or “lar par” for short, means that either one or both of the vocal folds does not fully open during breathing. The condition can occur in cats but is more common in dogs, and specifically in large-breed dogs. It can be hereditary in Bouviers, Huskies, Bull Terriers, Dalmatians and Rotweillers and is also commonly seen (but not necessarily hereditary) in Labs, Goldens, St. Bernards and Newfoundlands.
The first thing you might notice if your dog is suffering from lar par is a change in his or her bark, which might sound more hoarse, because the vocal folds are not moving as they once did. Due to the importance of panting, which is essentially moving air through the larynx, as a cooling function in dogs, you might also find that your dog has exercise intolerance and/or might breathe very noisily or heavily in warm weather. As well, when paralyzed, the larynx might not be able to protect the lungs from aspiration, so your dog may experience coughing, gagging and/or retching. In extreme situations, you may even notice respiratory distress or heat stroke. The clinical signs usually correlate with the degree of paralysis.
To diagnose laryngeal paralysis, your veterinarian will need to do a sedated exam and watch the larynx move as your dog breathes. Because the larynx is so deep in the throat, it is not possible to get a good look at it without sedation. A workup for lar par might also include blood work on thyroid levels, since up to 10 percent of dogs with lar par also have concurrent low thyroid. Chest x-rays may also be taken if your vet suspects aspiration pneumonia, which commonly happens with laryngeal paralysis.
The only treatment for laryngeal paralysis is a surgical procedure to tie back the laryngeal folds. This procedure, actually quite common with race horses, is called a “tie back” and is usually performed by a surgery specialist — so your primary vet may refer you to a specialty practice. The surgery can only be performed on a stable patient, so If your dog has a lar par complication such as pneumonia, he or she will likely be hospitalized until stable enough for anesthesia and surgery. The major risk of the surgery is an increased likelihood of aspiration pneumonia, since the folds will no no longer able to completely close and protect the lungs.
Lar par is a disease that can range in seriousness from minimal clinical signs to severe respiratory distress and even death. If you notice any of the hallmark signs, such as a change in bark, increased respiratory noise, or exercise or heat intolerance, please bring this to the attention of your veterinarian. It is very important to note that dogs with this condition can overheat easily, so they should be kept in an air-conditioned environment and have limited exercise until they can be examined and/or have surgery. The good news is that after tie back surgery, dogs usually do quite well.
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