A friend of mine recently set out to hike Pikes Peak with his trusty companion, a nine year old Lab named Donald. In his younger days Donald would run circles around the hikers as they huffed and gasped up the hills, but recently although the enthusiasm remained, he seemed to be losing a step or two. The hike started out as always, with a wagging tail and lots of bounding, but by Barr camp Donald was diving over to any pool of shade he could find and flopping down. Eventually it became clear that this dog wasn’t walking anywhere anytime soon. This poses a bit of a problem when you are many miles up the side of a mountain with a ninety pound dog who has lost his go power. The episode ended with an unplanned overnight stay, a trip back down the mountain and back up again with a stretcher for the dog, and a lot of tired, cranky people.
Although lack of conditioning and arthritis often contribute to this sort of episode, in this case heatstroke was the main bad actor. Donald had been developing a problem often associated with aging large breed dogs known as laryngeal paralysis. His owner had been noticing that Donald had been panting more often and more heavily, even when it wasn’t all that hot out. The panting was also noisier, almost with a roaring sound. Donald seemed to be otherwise normal, so his owner wasn’t too worried.
When dogs are getting overheated they do not have the luxury of sweating like people do. Instead they rely entirely on panting to move lots of air over their tongues to dissipate excess body heat. This system works well as long as all the components are working correctly, but if anything impedes a dog’s ability to move air over its tongue the cooling mechanism breaks down. When a dog inhales there are two flaps in the upper airway that are pulled to the side like opening French doors to allow the air to go in. With laryngeal paralysis one or both of the French doors progressively looses its ability to swing open fully and the dog has difficulty getting a full breath of air past the obstruction. There is often a roaring noise from the upper airway as the air rushes past the partial obstruction. If there is enough blockage of the airway the dog will not be able to pant efficiently enough to cool himself on a hot day or while exercising and heatstroke can occur. If you own a breed of dog that could be described as smash-faced, for example a Bulldog, Pekinese, or Pug, their crunched up upper respiratory anatomy can also lead to impaired panting efficiency and a greater predisposition toward heatstroke even under conditions where non smash-faced dogs would not be having problems.
The best way to handle a dog that may be prone to heatstroke is to recognize the potential for problems and to avoid being out during the heat of the day. Make sure your dog is still able to handle shorter hikes before getting five miles into the 10 mile hike and being faced with giving your St. Bernard a piggyback ride to get her back to the car. If your dog collapses with heatstroke and you can get to a veterinarian, do so immediately. If you are out in the middle of nowhere find some shade and put cool water on your dog’s foot pads and neck in particular. Completely submerging an overheated dog in cold water can cause some serious problems. Heatstroke can cause permanent damage or be fatal, so don’t run the risk if you can avoid it and don’t delay treatment when it happens.
Depending on the degree of the problem there may be some surgical fixes for dogs with upper airway obstructions either from laryngeal paralysis or smash-faced anatomy. In Donald’s case he didn’t require anything quite so extreme , he just had to join the rest of us in admitting that there are now some limits to what he can do. His second career in keeping the couches weighted down so they don’t float up to the ceiling is working out quite well for him.