Interestingly, Dr. Johnson found that 19 percent of the dogs examined because of cough alone (no upper-airway signs) also had some form of laryngeal dysfunction, ranging from laryngitis to swelling to laryngeal paralysis. Dogs with an acute cough were not observed to have laryngeal inflammation, but it was noted in more than half of the dogs who had been coughing longer than two weeks.
Results also indicated that dogs with a cough of more than two weeks’ duration commonly have laryngeal swelling regardless of the underlying problem. This makes sense, as chronic coughing irritates the throat. Laryngeal paralysis or partial paralysis was also fairly common, seen in 19 percent of the dogs with a cough of more than two weeks’ duration. Remember, these dogs had none of the classic signs of laryngeal paralysis (such as excessive panting and loud breathing); the problem was only diagnosed when their throats were scoped.
Once their laryngeal problems were correctly diagnosed, the dogs received focused testing and treatment.
In dogs with laryngitis, treatment includes antibiotics if appropriate, as well as anti-inflammatories and pain medication. (Laryngitis hurts!) When the inflammation is caused by allergies, the allergies are addressed. A dog with a swollen larynx also benefits from humidified air; a warm, clean environment; and soft food. Dogs with a weak or paralyzed larynx can be treated surgically, or may require hormone therapy; there is anecdotal evidence that laryngeal paralysis may be related to hypothyroidism. Those whose dogs have laryngeal paralysis need to be advised on how to prevent overheating and aspiration pneumonia as well as informed of the links between paralysis and systemic neuromuscular diseases and megaesophagus.
The finding that dogs can have laryngeal disease even when they don’t have the classic signs has significant implications. If we as veterinarians aren’t scoping these coughing dogs, we might be missing something. The bottom line: if your dog has been coughing for more than two weeks, or if the cough doesn’t resolve with medication, talk to your vet about further medical evaluation.
*Johnson, L.R. 2016. Laryngeal structure and function in dogs with cough. JAVMA 249(2):195–201.