The biggest risk for heatstroke is the dog’s immediate environment. If your dog is in very humid conditions or a confined space without fresh air (such as a car), they will quickly overheat. Brachycephalic breeds of dogs (those with short muzzles e.g. Bulldogs and Pugs) are also more prone to heatstroke because their nasal passages are smaller and it is more difficult for them to circulate sufficient air for cooling.
Early signs of heatstroke include:
If your dog’s body temperature reaches above 40 degrees or it is exhibiting the above symptoms, apply immediate first aid. The most important thing is to get their body temperature down to a normal level.