How can heat effect dogs? How do dogs sweat? Ho do dogs cool down in the heat? Can some dogs tolerate the heat better than others? Do brachycephalic dogs struggle more in the heat? Why do some health conditions have an impact on a dogs tolerance of the heat?
Most of us enjoy spending some time in the sun and we are much better equipped to cope with the heat than our dogs are. We can dress appropriately, and we can sweat from all over our bodies (when we are too hot our bodies transfer some of this heat into the liquid sweat which then evaporates into the air, thereby cooling us down). We also understand the dangers of overheating and can ensure that we’re drinking enough and seek shade when necessary.
Dogs don’t have this understanding and prefer to be with us, joining in our activities and trying to please us.
They are also, of course, wearing a permanent coat.
Dogs can only sweat through their paws and these paws are often stood on a hot surface.
Panting can help to cool dogs down, but it only has limited effectiveness, particularly with flat-faced (brachycephalic) breeds – more on this later.
But why do some dogs tolerate the heat better than others?
Dogs that are very old or very young will be less able to cope with the heat, as will dogs that are overweight. Health conditions will have an impact on a dog’s capacity for heat tolerance, particularly heart and lung conditions. The type of coat a dog has will make a difference too – darker coats will absorb the heat more, whereas a white coat will reflect the sun’s rays.
Double coated breeds such as Huskies, Golden Retrievers, German Shepherds and Newfoundlands are insulated from the sun’s harmful rays. It is important that you never shave a double coated breed or cut their topcoat short. Instead, groom them regularly to get rid of loose fur.
More significantly than all of the above, dogs that are flat-faced (brachycephalic) have a much higher risk of heat-related illness. Brachycephalic breeds include the Pug, Chihuahua, Pekingese, Boston Terrier, most bull breeds including the French Bulldog, Boxer, Cavalier King Charles Spaniel, Chow Chow, Lhasa Apso, Bullmastiff and Bichon Frise.
But why? What is different about these breeds?
Many owners of these breeds are unaware of the issues they face. They have shorter skulls which gives them the flat faces, underbites, widely spaced eyes and shallow eye sockets.
All flat-faced breeds suffer from BOAS (Brachycephalic Obstructive Airway Syndrome) to some degree. The soft palate is too long for the shortened nose, causing the throat to be partially blocked. The windpipe is also narrowed. This means that these breeds all have breathing difficulties, often snoring, open-mouth breathing and gagging. They struggle to breath effectively in the heat and when exercising.
Panting is less efficient than in other dog breeds and does not give these dogs the amount of air that they need; they simply cannot get enough air in or enough heat out.
Intolerance to exercise often leads to dogs that are overweight which further exacerbates the problem.
Heart conditions are much more common in flat-faced breeds. For example, Boxers may suffer with Aortic Stenosis or Arrhythmias, English Bulldogs with Pulmonic Stenosis and Cavalier King Charles Spaniels with Mitral Valve Disease.
Gum disease increases the risk of heart disease too and flat-faced breeds have an increased risk of dental problems because of the overcrowding caused by a shorter upper jaw.
So, as soon as the weather starts to warm up (anything over 20 degrees), please consider not only the time of day that you’re walking your dog but also the dog’s breed, age, any health conditions, it’s fitness level, what type of coat it has, as well as where you are walking (i.e. amount of shade), the humidity level and the type of exercise your dog is doing.
If you would like to learn more about the health issues you should be aware of in flat faced breeds, we have a self study module on this topic which you can access here.
