Q. I appreciated your June 2019 article on how to surgically fix the labored breathing that comes with laryngeal paralysis, which affects a significant number of older, larger dogs. But I also heard about a drug to treat the disease and make breathing easier. Can a drug really take the place of an operation?
Dear Ms. Locke,
A. The drug you’re referring to is doxepin, which is an anti-anxiety medication. When a dog gets into a breathing crisis, say, in hot weather, she will panic (just like a person struggling for air). And that only makes it that much harder for a dog with laryngeal paralysis to breathe. She ends up sucking the larynx shut, which means oxygen can’t easily move from the mouth to the windpipe. (Think of a straw collapsing to a close when you suck too hard.) The harder the dog tries to breathe, the more tightly the larynx shuts and the more anxiety that results — it’s a vicious cycle.
The thinking is that doxepin can reduce anxiety in general and perhaps control breathing better by helping to make sure a dog remains calm when breathing gets tough. At this point the evidence is anecdotal. A clinical trial is testing the drug in dogs, but results won’t be out for a while. If the medication does prove to be helpful, it likely wouldn’t take the place of an operation to treat laryngeal paralysis in dogs with severe breathing problems, but it might be able to delay the surgery or at least keep a dog a little more comfortable until the surgery takes place.
We should note that laryngeal paralysis is a component of body-wide nerve damage, not just nerve damage in the larynx. The condition as a whole is known as Geriatric Onset Laryngeal Paralysis Polyneuropathy, or GOLPP. A disease of the peripheral nerves (rather than the brain or spinal cord), it can lead to such symptoms as weakness in the hind legs. But owners will often notice the labored breathing first. It’s not known if the laryngeal nerve (one of the longest nerves in the body) is affected first or if its malfunction is recognized first because breathing is such a critical function.