Dogs and cats have a rather inefficient system of losing heat. Their skin surface is covered in hair and they do not sweat. They lose heat by drawing air over a greatly expanded moist tongue. The evaporative effect cools the blood in vessels close to the surface of the tongue.
In extreme temperatures this may not be sufficient to prevent a sharp rise in the general body temperature, and signs of heatstroke may become apparent. The dog becomes very restless, and throws itself on its side only to get up a few minutes later to find a new spot.
Its respiration becomes more rapid and noisy, and the tongue, instead of being covered with saliva, will be quite dry. The color of the tongue changes from a healthy vivid pink to dark red and then blue. If urgent measures are not taken to reduce the body temperature, the pets may die.
Aged pets with failing hearts are, of course, most susceptible to heatstroke. Dogs or cats that become very excited with car travel are also at risk, but even a healthy young pet may succumb in extreme conditions.
Most pets are lost with heatstroke through being locked in a parked car. Owners are often surprised how quickly their pets start to become distressed. The temperature within a car rises very quickly with only a small portion exposed to the sun and even with the windows partially down. While actually travelling the portion of the car allocated to the pet may not be very well ventilated.
Dogs may become affected by the heat when vigorously exercising or playing. The excitement of being with its owners or the desire to keep up may bring about a dangerous rise in temperature. If water is not available for frequent drinks to wet the surface of the tongue the problem is exacerbated.
Treatment of heatstroke is simple but must be carried out as a matter of urgency. Do not waste time looking for a veterinary surgeon if your pet is distressed and the color of the tongue bluish.
If at home, the floor of the bathroom or laundry is most suitable. If outside, choose the shadiest spot available preferably on moist ground. Wet the dog completely with cold water and keep the tongue and mouth tissues moist but do not try to force the pet to drink.
After a short time the rate of respiration should decrease and the tongue should become a more normal pink color. If the pet is not completely normal within a short time, consult your veterinary surgeon.
When travelling with a pet, make sure that you carry a good supply of clean water and a bowl. At each stop offer the pet a drink and allow it out for a short walk. If it is inclined to become very excitable or become carsick ask your veterinary surgeon to prescribe a suitable tranquilizer.
Pets being left at home during summer months must have access to a completely shaded area. They must have a plentiful supply of water which cannot be knocked over and they should be exercised during the cool of the early morning or late evening.
Do not leave food scraps to attract flies, but make sure that the pet cats when offered food, and remove any unfinished meal. Two small meals, morning and evening, are probably better than one large meal in very hot weather.