Dr Liesel van der Merwe is a small animal medicine specialist. Send her your questions: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Dr Liesel van der Merwe

Well, stating the obvious, it is hot. I’m threatening to emigrate to Scotland, just for the cold weather. When it comes to your pets in this very hot weather, the best is to just leave them be. Most dogs have enough common sense to keep themselves cool on hot days. It’s when we play with them or exercise that things may get pushed beyond normal.

Heat stroke or heat exhaustion is a very serious condition and can have catastrophic consequences even if we do get the patient’s temperature down. Temperatures of 39°C and higher are above normal.

If the temperature continues to rise and reaches 41°C, the rise is dangerous. Once a certain point has been reached, there is damage to the cells of the small capillaries and an inflammatory and excessive blood clotting state ensures, which ultimately results in organ failure.

My advice is to not do much with your dogs at all in this weather. Cats obviously are less of a problem – mainly because we don’t walk them, travel or exercise with them. They know how to handle the heat – stretched out in the shade on the cool tiles; the longer the cat is stretched out, the hotter the day.

Our pets don’t sweat, they’re polite that way. Evaporation of sweat on the skin is an important cooling mechanism for humans. Dogs and cats can only sweat through their paws. They use the evaporation of saliva and breathing as a means to cool down. I’m sure we’ve all seen on a hot day, or after exercise, how our dogs’ tongues seem double normal size. This is to increase the evaporative surface to maximise cooling.

Certain breeds are also predisposed to heat exhaustion – most notable the flat-nosed breeds (brachycephalic dogs), as they cannot breathe efficiently and thus cannot cool easily. As they struggle to breathe, the tissues at the back of the throat may swell slightly and this further impacts on their breathing. You average Pekingese dog is at less risk than the active brachycephalics such as boxers and Staffordshire terriers, who may over-exercise in the heat.

Dogs with very thick coats are also obviously not designed for this hot weather. However, it is not a good idea to clip the dogs with these double coats, but rather comb and strip out the undercoat, leaving the longer hairs which will act to actually keep the dog cool. It works like good insulation – cool in summer, warm in winter. If you clip these dogs they grow a thicker undercoat and you lose the longer hairs.

Humidity is thus another factor to take into consideration. If evaporation from breathing cannot occur due to high humidity, then heatstroke is a greater risk even without exercise or activity.

Early signs of possible heat stroke include decreased responsiveness, glazed eyes, excessive drooling, a rapid heart rate, dizziness or lack of coordination, fever, lethargy, and loss of consciousness. Advanced signs are collapse, convulsions, they exhibit vomiting or diarrhoea and also gums or a tongue which turn blue or bright red.

At the first sign of overheating, immediately take action to cool down your dog. If the signs seem more advanced, you need to start the process of getting him to the vet as well. Move your dog to a cooler area with shade. If possible, place a fan directly on the dog.

If you are away from home, travelling, the best place may be in the car with the air conditioner on. If you are near water and your dog is not afraid of water – put the dog into this water. Otherwise wet him down with wet towels.

Areas with thin skin allow the best temperature loss, so make sure the feet, ears, armpits, groin and tummy skin are all wet. Allow cold drinking water, but do not force if they are not swallowing. Do not feed ice cubes, as this will cause overcooling. You can, however, use ice cubes on the tongue.

Once the dog is wet, place a fan on the dog. If the dog is very hot, I also use alcohol to rapidly cool, as it evaporates quickly. However, this is surgical alcohol, so your aged whisky will not help.

An ice bath or ice water all over the dog is not recommended, as this may cause vasoconstriction, thus shunting blood away from the skin and slowing cooling. If ice or ice packs are available, these can be wrapped in a cloth or paper and placed in the groin or armpits. This will cool the blood in the major blood vessels in those locations. The blood vessels are too big to constrict.

Lots of anxiety and stress can make the whole situation worse. Keep as calm as possible and this well help to calm your dog. Stress makes the symptoms worse.

With heat stroke, prevention is better than cure. It should go without saying: don’t leave your dog in a parked car. Limit outdoor exercise on very hot or humid days. Lots of shade and water must be available. If your dogs want to exercise, use the garden sprinkler to cool them as they play. Make available plastic shells or baths with water in, so they can have a dip when necessary.

If you go on walks or take your dog running, you need to only do so very early in the morning or in the cooler evening hours. If you’re hot, they’re hot. If you are gulping down water on a walk or hike, they’re often not, and that is a risk factor. Naturally a dog will stop running and rest intermittently when overheating. We, however, carry on running our route and manage the temperatures better as we are sweating and cooling this way as well as drinking water.

If you and your dog often go for long runs, you can use cooling vests when the temperature or humidity is high. These vests either gradually soak and evaporate water, thus cooling, or they have a gel compound in their structure which, once ‘activated’, keeps the dog cool. They are a very good idea for working dogs as well. Gel cooling mats are also available and these are ideal for travelling or just using in the home.

The bottom line is to allow your dogs to rest and stay in a cool place during the hottest part of the day and don’t underestimate the heat in the later afternoons, especially if it is humid.