by Ben J. Character, DVM
My 12½-year-old female Labrador has been diagnosed with laryngeal paralysis , although she has never actually had any sort of test to determine this (I don’t know if there even is a test). But this is the diagnosis the vet has made.
Laryngeal paralysis is not an uncommon problem in older Labradors. Found just distal to the oropharynx, the larynx is the entrance to the lower respiratory tree. It houses the epiglottis as well as the vocal folds, which are both active in protecting the lower respiratory tract from the entrance of foreign materials. It is the “gateway” to the lungs.
There are a few different nerves that control the larynx from both the somatic (conscious control, i.e. vocalization) and autonomic (unconscious control, i.e. closes airway during swallowing) nervous systems. The area has a structural system of cartilage creating a semi-rigid passage way for airflow.
In laryngeal paralysis, there is a dysfunction of nerve supply to the larynx. This can be unilateral (one side) or bilateral (both sides). Bilateral dysfunction is usually very noticeable and can even result in a dog being presented in respiratory distress. On the other hand, when there is only unilateral dysfunction, symptoms are often more subtle in nature.
Either way, the primary symptoms are related to a reduction in the ability to regulate airflow and keep the airway clear of contamination (e.g. water, food, etc.). Diagnosis of laryngeal paralysis is not too difficult once the presumption has been made.
In most cases, after carefully placing the dog under anesthesia so that the epiglottis can be retracted out of the way, the vocal folds can be visualized to assess function. At this point, if neither of them are moving and instead simply sitting in the airway, this indicates bilateral dysfunction. With unilateral dysfunction, one fold will be retracted back while the other is found in the path of airflow, creating problems.
Given her heavy breathing when exercising or when excited, it seems like a reasonable diagnosis. Plus she started having mild regurgitation after eating. So now all she gets is soft food or soaked hard food mixed with extra water, plus we raised her food bowl. She also gets her meals divvied up into small meals throughout the day.
Laryngeal paralysis will commonly cause an increase in respiratory noise even during normal activity, much less during exercise. However, regurgitation alone is not a typical symptom. Sometimes, because of the tendency for food to get into the airway when there is laryngeal paralysis, this can make a dog gag and hack. Raising the food bowl is advisable for a dog with laryngeal paralysis and can sometimes be a quick fix for mild cases. If gaging secondary to mild aspiration is what is really going on – in contrast to actual regurgitation – then it would certainly fit with laryngeal paralysis. But, if you are seeing true regurgitation and you had a firm diagnosis of laryngeal paralysis, there could be a more significant underlying problem called dysautonomia. Briefly, this is a malfunction of the autonomic nervous system, which, with these symptoms, is supposed to control the swallowing and laryngeal functions (along with many others).
She has had her lungs X-rayed twice recently when the breathing became worse and we feared aspiration pneumonia. Her lungs were fine. Also all blood work was fine. At that time, however, we finally also realized she had a UTI. So, I am now wondering if the unusually heavy breathing in that specific instance may have been pain related. Also, the procedure on her bladder for the UTI (cystocentesis) didn’t find any stones, but I was informed that was not conclusive and would need further testing if the blood in her urine continued.
It is good that the radiographs did not show signs of pneumonia. Aspiration pneumonia is a commonly experienced problem with laryngeal paralysis secondary to food and water getting past the larynx and into the lower respiratory tree. Regarding the UTI, these can be painful, and panting and tachypnea can both be a result of pain. Bladder stones are a common cause of UTI and would have to be ruled out with a radiograph of the bladder. There is no reason to suspect that a laryngeal paralysis would create a higher incidence of UTI development.
She is currently on a low dose of Prednisone, 2 mg a day for 14 days, and then 2 mg every other day for 60 days, hopefully to help the paralysis. She also gets 300 mg of Gabapentin twice a day for pain and stress. She is a very high-strung dog – when we take her to the vet, she is always so hyper it is impossible to really even get a good temperature reading on her, and of course her breathing is awful. In fact, it scares the vet techs who do not know her.
The respiratory distress and struggle seen with a laryngeal paralysis can be quite unnerving. It is advisable to get a definitive diagnosis and then have corrective surgery done if found. During corrective surgery, the effected vocal folds (via supporting structures) are pulled back and secured so that they are no longer in the airway impeding airflow. This will greatly improve respiratory function; however, it will also make the lower respiratory tree more susceptible to having an inappropriate substance enter, a necessary trade off.
Most general practitioners do not perform surgical treatment for laryngeal paralysis because they are uncomfortable with the risks of anesthesia for affected dogs, as well as the technical difficulty and risks of nerve damage associated with the procedure. Because of this, most veterinarians will refer laryngeal paralysis cases to specialty centers.
I feel so helpless to help her. Sometimes she wakes up in the middle of the night and starts with the heavy breathing, and there is nothing I can do but sit up with her until it stops, usually after an hour if I am lucky. I don’t know why she does this either. She is sometimes suddenly completely wired at 3 a.m.!
No one can really answer this question, but I like to think of it as a little like having really bad sleep apnea. If you are asleep and then suddenly you can’t breathe, you wake up with a significant adrenalin rush. I sympathize with your situation and would encourage you to seek a definitive diagnosis and treatment.
