I posted this in another group forum to answer someones questions and concerns, and since I already took the time to write it up, I thought it may be beneficial to re-post here. Summers in WA only seem to be getting warmer and longer and that can put us and our canine compatriots at risk:
I've spent the last decade providing direct medical support to military working dog teams in both a clinical and point-of-injury (field) environment at home and abroad. I have personally treated at least two dozen cases of severe human and canine heat stroke. Not to humble-brag but provide some background so you can decide if my 2 cents worth of rambling is valuable to you. This will be long for a Facebook comment, in an attempt to be as informative as possible.
There is a good article published in the Journal of Special Operations Medicine regarding heat injury and SOF Multi-Purpose Canines. If you happen to have a subscription to JSOM, you should check it out (https://www.ncbi.nlm.nih.gov/pubmed/22707020). If you do not, read on.
Heat injury is historically one of the top three canine casualty causing events in a deployed environment and the leading cause of canine casualty in a garrison/training environment.
To mitigate this risk a lot of research, development, and training has been put into canine heat injury in the military. The normal reference range for core canine temperature, usually measured by rectal digital thermometer, is 100.5-102.5 degrees Fahrenheit. A lot of dog’s internal temperature exceeds this range from excitement or exercise, with some dogs "working temperature" exceeding 105/106 degrees Fahrenheit, without any signs or symptoms of heat injury.
There are three categories of heat injury: Heat Stress, Heat Exhaustion. and Heat Stroke. These terms and their corresponding number value for temperature aren't really that important. Unless you want to carry a thermometer on you and get your dog accustom to taking his/her temperature regularly, you know, rectally. Which I would recommend.
As many of you are already familiar, common signs and symptoms of heat injury begin with "shade hunting" and excessive panting then progress to being unresponsive to commands, hyperventilation, collapse, and seizure to name a few. Most people can recognize when their dog is in distress like the OP and other commenters.
We routinely monitor the dogs “resting” and “working” temperature, that way if the dog is exhibiting signs and symptoms of heat injury, we check their temperature and see if it corresponds with their normal values. With the caveat that if the dog appears to be a heat casualty with no other outward signs of trauma or illness, but the thermometer says 102 deg, for example, I will treat for heat injury regardless as first response.
Physical conditioning and hydration are the two most effective methods for heat injury prevention. If your dog doesn’t hydrate regularly, baiting the water as people have suggested can help. There is another interesting research article regarding working dogs on our Southern border and maintaining hydration (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5662554/)
A lot of cooling vests tested in various studies have actually made the dogs hotter. One that I have had success with is by Ruffwear, I don’t get anything from them for saying so, but I’d take it if they did!
If heat injury has occurred, the goal of treatment is to stop progression. The most effective means discovered by the veterinarians and medics conducting the study were ice sheets. Basically, a towel or cloth of some kind kept in a cooler filled with ice and water and placed over the dog, which was contrary to popular belief beforehand. Submersing or covering in cool or cold water is secondary, then instant ice packs in the armpit and groin are also effective as my personal third choice. Alcohol on the foot pads/ears/skin etc. is insignificant in my experience, but a worthwhile attempt if that is all that is available.
Obviously carrying a cooler full of ice water and sheets is not realistic for hiking/backpacking so I recommend 2-4 instant ice packs with some extra water, which is what I carry in my aid bag if on foot and mobile.
Another phrase I’ve always remembered from a veterinarian was “Wet and Windy.” Get the dog wet and find a way to move air over them to evaporate heat. The best way to do that is cover in water and put in car with AC on or windows rolled down at speed. Or helicopter, if that’s how you happen to get to the trail head.
Whatever method of cooling you have available, it is also important to stop cooling measures a few degrees before reaching the target temperature of 102/103 to prevent rebound hypothermia. During a heat casualty we monitor the patients (human or canine) temperature every 2 minutes to know when to stop actively cooling and continue to check temperature to verify thermoregulation. Sometimes heat injury can kind of “break the thermostat” and after you have cooled them successfully, their temperature can shoot or creep back up.
Is this excessive for the average dog enthusiast in the back country? Probably, but the more you know...Also, it keeps getting hotter in WA during the summer, evidenced by the AC unit my house has that it wouldn’t have had 15 years ago. If you read all of this, hopefully it was informative.
P.S. A good field test if you think your dog is getting heat stressed is to hold your dogs favorite toy or treat in front of their nose, if they close their mouth and intently stare at the best thing ever, they are probably OK. If they can’t stop mouth breathing they might be getting/are heat stressed.