As the temperatures begin to rise, it is a good time to look at the subject of temperatures when it comes to running dogs in harness and sled dog related activities. The first thing to remember is that this is a winter sport. For many mushers of the far north the time to stop thinking about running sled dogs is when it gets so warm the snow melts. For those of us in more temperate climes the opportunity to run when temps are near cold enough for snow in the heart of winter is a rare occasion.
I think the first thing to be very clear on heat stress is one of the biggest dangers to a healthy dog in this sport, dogs have a very inefficient cooling system, they cannot sweat except through their paws and their main heat release mechanism is panting. A dog suffering heat stress can suffer long term organ damage or even death simply from not being able to cool down properly or being active at too high a temperature for too long.
Many factors can effect a dogs ability to cope with heat stress and there is no simple answer other than to watch your dogs very carefully for signs that they are over heating and act quickly. In Dryland races, most races will be stopped if the temperature reaches 15 degrees C, additionally if the temp is over 12 degrees C the trail length is often cut to just a mile or two in length. As well as temperature, humidity has an important part to play as dogs expel vapour from their mouths in the form of panting to release heat, this becomes increasingly hard the higher the humidity as the air is already full of moisture so the system becomes more inefficient. This is the same for us when we sweat, if the air is warm and humid sweating often makes us still feel uncomfortable as the evaporation effect doesn’t take place to cool us.
As well as environmental factors, acclimatisation of the dogs is also a big factor. Dogs acclimatised to temperatures will generally cope with them better, this is important to bear in mind when temperatures start getting warmer. The same dog may well cope with a temperature and humidity factor at the end of summer which could be dangerous in spring as they are acclimatised to colder temperatures. Many other factors can also affect a dogs ability to cope with temperatures, entire dogs tend to carry more muscle and heat up faster than castrated dogs for example. Heavy coated dogs will lose less heat through their fur than lightly coated dogs too and find it harder to cool down after exercise. There are far too many variables to go into here and they are often so dog specific it is more important to recognise the signs of heat stress and know how to respond to cool a dog down than anything else. The golden rule though should be if you’re not sure whether its too warm then go steady, keep it short and really pay attention to your dog, some dogs will literally just cruise along in warmer temps and protect themselves, others will get so excited they go hell for leather and literally run till they drop.
Here are some links to useful pages and websites to find out further information:
Canine Casualty Care – a FB page with lots of information on heat stress and other canine related injuries https://www.facebook.com/groups/2397740840549779/?ref=share
Canine Health Foundation – https://www.akcchf.org/canine-health/sporting-field-dogs/hyperthermia-in-dogs-fast.html
Above all please take care and don’t assume that just because your dog is short coated it can cope with the heat better. Enjoy your dogs, have fun, but do take care.