Veterinarian Michael Lechnik of the Small Animal Clinic in Vienna, Austria, explains here what dogs, rabbits, and the like when exposed to extreme heat.
[An edited transcript of the interview follows.]
At temperatures as high as 37 degrees Celsius (99 degrees Fahrenheit), we humans sweat a great deal of sweat, which is just too stressful for some. How do you deal with pets?
The heat is also stressful for them. However, unlike us, most of them can’t sweat.
Why is sweating important when it’s warm?
When we sweat, the heart pumps more blood through the body, blood vessels and skin pores expand, and the sweat produced by the sweat glands comes out. When it evaporates, it helps us maintain a constant core body temperature. Dogs and cats also have sweat glands on the balls of their feet, but it’s not enough. On the other hand, pigs and rabbits do not have the ability to sweat at all.
What strategies do animals use instead?
They differ. Many pant, first and foremost. The movement of rapid breathing causes the throat to secrete saliva, and the evaporation cools. The body also releases heat by exhaling and the nasal secretions produced by gasping. This is especially evident in dogs, but birds and cats can also pant. But this breathing technique is laborious and causes the animals to expend more energy.
Does panting regulate internal body temperature for only a short period of time?
Other methods are needed. Cats, for example, are increasingly licking their fur. This makes them moist and evaporation leads to cooling. Most animals also like to take a shower, look for a place in the shade, shift physical activities into the morning and evening hours, and drink more than usual. Basically the same strategies we have as humans.
Why is rest so important to us and animals?
Exercising causes the body to produce heat. To avoid overheating, the body must dissipate it, and this costs energy. So most animals instinctively recede in the heat. Only dogs don’t find this easy.
What distinguishes dogs from other animals in this regard?
Their close relationship with humans. Vigorous domestication has deprived them of many of their instincts. If I go jogging with my dog in 37°C weather or let the animal run next to my bike, it will go along with it. This is because dogs are designed to track their owner or owner. This is why there are always dogs that fall apart even though there is a lake nearby.
Does this have anything to do with their domestication?
The animals I’m talking about don’t cool off in the shade or splash in the water, but are kept occupied by their mistress or master for hours as they retrieve a plate of Frisbee. Few jumps into the water no longer compensate for the heat their bodies produce through movement and high temperatures. Neither the dogs nor their owners realize they need a break. It is different for cats: they are no longer black, but they have largely retained their instincts; It is difficult to motivate them to play in the hot sun. The same applies to rodents or birds.
Speaking of which, what about guinea pigs, mice, and rabbits? How do they deal with heat?
They also need rest, shade, and plenty of fluids. Instead of panting, some of them also use their ears. It is equipped with a network of tiny blood vessels. At higher temperatures, the vessels expand and thus heat is dissipated. Unlike dogs and cats, ferrets are often kept in cages or outdoor enclosures. If this happens during the day directly in the sun without resorting to a shaded haven, cooling over the ears or increased drinking is not enough. Then these animals also run the risk of overheating. The same applies to birds and fish. It helps to cover parts of enclosures or aquariums with a cloth.
So anyone who takes care of a pet should make sure there are cages in the shade?
And remember the course of the sun. After all, it moves throughout the day, changing the intensity of the sun’s rays. Sometimes it helps to cover parts of animal enclosures or aquariums with a piece of cloth. In addition, with fish, the water should always be controlled: if the temperature rises too much, it is important to add cold water. This is because heat also reduces the oxygen content. This causes stress, and in extreme cases animals lack the oxygen they need to breathe.
Does it also depend on the breed whether the heat is hard on a dog or a cat?
Pugs, bulldogs, and Persian cats have a particularly hard time. Through breeding, their skulls, especially the nose and upper jaw, have been shortened more and more. Adult animals keep their baby nose. The result is a narrowing of the nostrils and nasal cavity, an elongation and thickening of the soft palate, and changes in the larynx, which lead to breathing problems in many. This makes it difficult for animals to regulate their body temperature by panting. There is also an increased risk for pets that are very old, suffer from diseases such as diabetes, heart problems or are overweight. This is because subcutaneous fat cannot conduct heat well, which makes thermoregulation more difficult. In general, there is no fundamental difference from what happens to us humans.
What about animals that have a lot of fur, like long-haired cats? Do they suffer more than others?
not necessarily. Due to air circulation between the skin and the fur, long hair sometimes has a cooling effect. In addition, it protects hair from sunburn. However, it may be helpful to regularly remove the undercoat, which is the hair close to the body, by combing.
What else can you do to help pets during the hot summer?
Walk your dog in the cool morning and evening hours. The same goes for dog training sessions. Similar to birds, dogs also have the opportunity to bathe, and some like to shower gently with lukewarm water from a spray bottle. The rodents can be given a second water bottle to hang in their cage and provide more fresh green food. There is extra water in lettuce, cucumber, and pepper. Animals that are fed wet food, such as cats, should be offered small portions, as this food spoils quickly in the heat. It is also important not to leave animals in the car when it is hot, which unfortunately happens over and over again.
In the blazing sun, temperatures in the car quickly rise to over 70°C (158°F). An ajarred window and a small bowl of water were no longer sufficient for thermoregulation, nor gasping. Thus animals, usually dogs, can get heatstroke quickly.
What exactly happens during heat stroke?
Due to the rise in body temperature, the metabolism of the animal is stimulated more and more and becomes increasingly overburdened. From a body temperature of 42°C (108°F), vital proteins are also destroyed and eventually metabolism disintegrates. This leads to many organ failure, which in many cases can only happen after a day or two.
What can the owners do in the event of a heat stroke?
Common symptoms are increased salivation, balance disturbances, vomiting, diarrhea and even loss of consciousness. When this happens, they need to bring the animal to the shade, offer it water and cool it with cold towels. Often the animal also needs a veterinarian, and sometimes even stay in the hospital. Everyone who has an animal should be familiar with these first aid procedures.
Is there any other advice you would give to people who have animals?
Think about what’s good for you in the heat. This may also work for your dog or parrot. Because when it comes to dealing with heat, most animals are more like us than we think. If you are not sure, ask your vet.