13/07/2025
An experiment carried out by a vet on they own dog - showing how quickly dogs begin to overheat in hot weather.
8 minutes of free running off lead sent the dog’s body temperature up to dangerous levels. They then had to rest for an hour in the shade.
On lead Walking also had a similar effect but not as intense.
This was a 25c morning. So not full heat of the day when a lot of people walk their dogs. These are also very young, fit, and lean dogs that are accustomed to exercise.
This just shows how dangerous any prolonged exercise can be in the heat for healthy dogs.
Add in health problems (such as heart or breathing problems), excess weight, or even individual tolerance and it’s not hard to see how so many dogs come down with heat stroke.
So if you MUST walk your dog in the hot weather for toileting purposes etc, on lead, in the shade, for as short a time as possible.
These dogs were also thoroughly soaked with cold water afterwards - which can help with Evaporative cooling. So if your dog likes water, this could be an option to help keep them cool 😊
🔥 Hot off the press, part 1 🔥
EXERCISE-INDUCED HYPERTHERMIA IN HOT WEATHER 🔥
Another episode of How hot does Digger get...?🌡
🐾 8 min of running, 1 hour rest, 8 min of walking
⚠️ Warning and disclaimer, Digger did this experiment whilst being very closely monitored every 2min to demonstrate how quickly exercising dogs can get hot when temperatures increase to mid twenty degrees
⚠️ This experiment was recorded at 9.30am, not the hottest time of the day, and the air temp was already in the amber range according to the commonly shared temperature chart indicating the heat stroke risk for dogs: 8/10 risk "Extreme caution should be taken as most dogs, particularly those who are large, obese, flat-faced and very young, will find these temperatures VERY UNCOMFORTABLE"
👉HOWEVER....
🐕 In the world of dog agility, we often hear that our agility dogs supposedly cope much better in the heat than pet dogs, because they are fit, lean and should be acclimatised to the temperatures they are running in.
⏱️ The other argument, agility runs are short, less than a minute at max intensity, plus a short walk of 5-10min to and from the rings. The rest of the time agility dogs are resting in the shade.
So, let's measure it and track the body temperatures of 2 fit & lean agility-type dogs:
🌄 Measured THIS MORNING, 12th July 2025, 9.30am, as the temperature was getting warm (air temp ranged from 24.5°C to 26.0°C). Other dog walkers were out there, walking their dogs as usual.
📈 The Experiment: measuring the body temperature of Digger and Willow (a young rescue collie who is in foster) during a very brief run in the field. Digger was off-lead, foster Willow on a long-line.
Digger had his temperature checked at the start, then every 2 min during exercise, and every 15min during their rest period.
Willow's temperature wasn't taken during exercise, only at the start and during the cooldown phase. Digger's temperature curve in blue, Willow's shorter cooldown curve in orange.
Exercise was stopped when the first dog (Digger) showed signs of heat stress: the PADDLE TONGUE 👅 ⚠️🔥
AFTER JUST 6 MINUTES OF RUNNING Digger's body temp had increased to 39.4°C!!! (Or in fact more like 5 min of actual running because Digger had been recalled and stopped for 20-30secs at 2min and 4min to take his temp)
We walked straight back to van, and by 8min Digger's temperature had increased to 39.6°C.
Both dogs settled in the shade of the van and rested for 60 min - yes 1 whole hour of resting and enjoying the view (and editing the video!)
Although exercise had already been stopped and both dogs were resting in the shade, Digger's temperature continued to increase and peaked AFTER 10MIN OF REST at 39.7°C. Willow showed a similar trend, her temperature was 39.9°C at the end of exercise, and increased to 40.0°C after 10min of rest.
👉 EXCESS BODY HEAT GAINS MOMENTUM🔥, even after exercise is stopped. Digger and Willow confirmed that yet again today!!
The body temp of both dogs dropped back into the "normal range" (38-39°C) AFTER 45MIN OF REST. But even after 60min of rest, neither dog's temperature was as low as at the start of the experiment!
And just to mimic the reality of an agility show, where dogs would head back into the ring for their next run, we then went for an 8 min walk on lead. At the end of that, the body temperature of both dogs had increased to 39.3°C again - keeping excitable collies on a lead isn't enough to keep them cool!
Take home message:
🐕 Fit, lean, acclimatised dogs can and do develop exercise-induced hyperthermia after just a few minutes of strenuous exercise
🔥 both dogs showed emerging signs of heat stress after just 6-8min of running
📈 Excess body heat gains momentum, resulting in peak body temperatures AFTER exercise had been stopped (for 10min in this case)
🌞 In hot weather, dogs take much longer to cool themselves down (45min to return back "into the green" unassisted)
For anyone still reading this far, one might wonder, what was the point in doing this experiment? Is there any benefit for the two dogs?
Yes absolutely!
1. Acclimatisation training: Both dogs are (aspiring) agility dogs. Although they are not at a show this weekend, they are being trained to handle warmer weather - very short training runs in warm conditions whilst being closely monitored
2. For Willow who is new to the agility world: we are having to learn how she is handling warm weather, excitement and exercise. Willow is also learning to have her temp taken in the field and learning to settle and rest when she gets hot
3. Determination of exercise limits/ heat safety planning: the conditions today were near the limit where Digger would be allowed to run an agility run, WITH STRICTEST ASSISTED COOLING ROUTINES IN PLACE! As agility handlers, we all have to make assessments when it is too hot /humid for our dog to run, and where the limit is when we would withdraw the dog. To be able to make an INFORMED DECISION exactly where that limit is set for each of our dogs, we need to know HOW HOT our dogs get, and HOW LONG they take to cool down before they are back "in the green" and OK to run again.
🐕 KNOW YOUR DOG, KNOW THEIR LIMITS IN HOT WEATHER 🌞
🤔 DON'T GUESS OR ASSUME, OBSERVE THE DOG IN FRONT OF YOU, MEASURE THEIR BODY TEMPS IF NEEDED 🌡
And.. ALWAYS ERR ON THE SIDE OF CAUTION, COOL EXERCISING DOGS EARLY & RAPIDLY 💦 TO prevent heat injury in hot weather 🌞
Video of the experiment to follow, in part 2
