Laryngeal Paralysis (Lar Par) and Geriatric Onset Laryngeal Paralysis and Polyneuropathy (GOLPP)

     Laryngeal paralysis is a respiratory condition where the normal protective mechanism in the throat is malfunctioning, causing difficulty breathing during exercise/excitement and increased risk of aspiration pneumonia during any swallowing.  It happens because the muscles that control the laryngeal cartilages, the "barn doors" at the front of the trachea that open for breathing and close to protect the airway when swallowing, are not getting adequate nerve stimulation to function correctly.  Lar Par can be suspected by the harsh/louder than normal noise your dog makes when panting, and is confirmed by examining your pet's laryngeal cartilages under light and short-acting anesthesia with propofol anesthetic. It is usually a primary nerve disease, or neuropathy, and originally it was thought to be a problem only of the nerve supplying the laryngeal cartilage muscles.  For dogs, it is now thought that most Lar Par is part of a more generalized condition called Geriatric Onset Laryngeal Paralysis and Polyneuropathy, because most dogs with this condition are older and are also experiencing hind end mobility issues that are caused by nerve dysfunction rather than arthritis.  (These dogs may also have arthritis, but the main problem is a neuropathy of many nerves, hence polyneuropathy.)  
     Lar Par and GOLPP are progressive diseases; they start with mild signs and get worse over time.  Progression of the mobility problem is an important part of this, but the Lar Par issue needs the most management.  Often the Lar Par seems to suddenly get worse when warm weather arises because dogs must use their breathing to cool themselves down.  In cool dry weather there is not much need for this, so progression of the laryngeal dysfunction is hidden; when the weather changes and the ability to cool down by breathing faster is needed the problem becomes apparent.  Initial management of Lar Par is to keep your pet out of the heat and humidity as much as possible, often requiring air conditioning, and to limit exercise and excitement so breathing can stay slow and calm. (When the "barn doors" are not opening fully your pet is breathing through a bottleneck; this isn't a problem when breathing slowly and gently, but can be a very big problem if your pet needs to breath faster or harder.)  Additionally, the stress from any amount of struggling to breath through that bottleneck can trigger an asthma-like response where the airways in the lungs also close down, causing that small bottleneck to become a large bottleneck, and respiratory distress becomes respiratory crisis.  Sometimes anti-anxiety or mild sedative medications are needed to keep our pets from having respiratory crisis.
     In our journey with our own dog with Lar Par and GOLPP, Josephine, we have found some additional medical management.  The tricyclic antidepressant (TCA) drug doxepin increases levels of certain neurotransmitters in the brain and can help improve nerve function (all nerve function) in some dogs with GOLPP.  For some dogs the improvement within just a few weeks is dramatic, so it is definitely worth trying.  (Josephine had a so-so response, but is definitely better taking it than not taking it.)  We also found a combination of herbal/nutritional supplements that do seem to help Josephine with her ability to walk, so she will stay on them for life.  My personal belief is that starting doxepin and/or these nutritionals early in the course of the disease will be the most effective management.
    Progression of GOLPP varies from dog to dog, and for some eventually medical management of the Lar Par will not be enough.  For those dogs, surgery called a "tie back" is the gold standard, where one of the laryngeal cartilages is pulled mostly to fully open and "tied back" out of the way of the air flow.  This opens the airway for breathing, but does potentially increase the risk of aspiration pneumonia.  There are other types of surgery for Lar Par, but the tie back has the lowest overall complication rate so far.  The advantage of surgery is that your dog can breath easily without the risk of respiratory crisis which, if/when your dog gets to the point of having or almost having respiratory crisis, literally is saving your dog's life.  The disadvantage of surgery is that you need to schedule this with a referral surgeon, which may or may not mean multiple phone calls to find one who can accommodate your/your pet's schedule, travel to a referral facility while still trying to minimize stress, moderate cost, etc.
     An experimental alternative to surgery, or a temporary aid until surgery can be performed, is the placement of a sterile silicone stent.  Several papers have described small studies of dogs that have had a "tracheal" stent placed in the laryngeal area to hold the cartilages partly to mostly open, instead of the tie back.  The advantages of the stent are that your regular veterinarian can place the stent (he/she must be willing to learn how, but it has a very short learning curve; a couple long instruments are the only special equipment needed; and we will gladly help guide him/her); the cost is much less than for a tie-back; and the result is evident as soon as your dog wakes from anesthesia.  The disadvantages of a stent are that they must be ordered ahead of time, (your vet won't have these on hand otherwise); they are made in Spain so ordering is a little more complicated, (not horribly so, but most vets don't have any extra time as it is, so this may be an obstacle); the correct size for Lar Par is not the same as the size for tracheal issues so both client and customer service rep involved in ordering must be aware that this is for laryngeal paralysis; it does need to be sterilized prior to placement (but can be processed by your vet like other surgical instruments in an autoclave); it does require 2 long-handled instruments that many but not all vets have on hand so may need to be purchased specially for this; and the studies suggest the stent needs to be removed and replaced with a new sterile or a resterilized stent every 3 months.  
     We chose to place a stent in Josephine for a variety of reasons, including that getting her to a referral veterinarian without causing a respiratory crisis would be difficult due to our work schedule and her stress in unfamiliar places, and that we could try this ourselves without causing a crisis.  Our experience with Josephine with her stent has been very positive, but she is overdue for the replacement and she needs to have that done.  She has developed a local infection near and including the stent, making her breath smell like month-old gym socks, and will need to have the area flushed along with getting oral antibiotics for a few weeks when she has the stent replaced with a new sterile one.  Depending on the longevity of the 2nd stent, we may decide to schedule her for a tie-back after all.  
     And that brings up the subject of whether the stent is a permanent solution or a temporary one.  For one dog in one of the studies, the stent was in place for many years at the time of the write up; the rest were more recently through the experimental placement.  Even Josephine is less than 5 months into having hers, so long term issues are still unknown. My opinion is that for dogs that do not develop an infection and/or who do have the stent exchanged every 3 months (or as determined by their vet), this seems a viable alternative to referral surgery, where getting to referral surgery presents challenges.  But tie-back surgery has few complications and once done requires no follow up treatment, no replacements, no additional cost or vet visits.  So alternately, the stent can be a temporary solution to prevent a respiratory crisis while waiting for a tie-back or deciding how manageable the rest of your pet's GOLPP signs are if you are not sure about a tie-back, or until someone can come up with a better design for a stent, (one that is designed specifically for the laryngeal cartilages instead of adapting a stent designed for tracheal issues).