ByUniversity Professor in the Area of Animal Physiology, University of Malaga
The arrival of the summer time divides humans. While some associate it with vacations, fun and outdoor activities, for others it means seasonal work, mosquitoes or excessive tourism. But there is something that we all experience equally: heat. And that does not exclude our pets.
The most faithful friend of the human being, The dogIt does not have the same mechanisms as us to face high temperatures. So how do dogs deal with the summer cannula?
Homeothermia in dogs
As sure they will know, the dog (Canis familiaris) descend from the wolves (Canis lupus) that, with some exceptions, they are mainly distributed by regions of temperate and cold climates. In the evolutionary process of the dog’s appearance, he inherited from the wolves not being especially well adapted to heat. However, it must be borne in mind that thousands of years of selective breeding have resulted in a huge variety of dog breeds and each of them has its particular characteristics.
Dogs, like us, are Homeothermal animals. That is, they control their body temperature within a narrow range (where appropriate, around 38.5⁰ c). This implies an energy expenditure on physiological thermoregulation mechanisms. But, on the other hand, it provides the advantage that all our biochemical and physiological processes can always occur to the same temperature and with maximum efficiency.
Another detail that we must keep in mind is that all living beings, including the tiny bacteria or the most motionless plant, generate internal heat as a product of our metabolism. In other words, the simple fact of being alive implies that we are constant heat factories.
Dog gasp is the equivalent of human sweating
When temperatures squeeze, our body has a hard time transferring the heat we produce to the environment around us, so it accumulates and we heat more and more. If the ambient temperature is higher than the body, we even tend to capture thermal energy from abroad, adding to which we produce.
In these situations, the only effective way that a terrestrial animal can have to cool is through evaporation. The water on our skin absorbs part of our thermal energy to travel from the liquid state to the gas.
We humans have effectively take advantage of this mechanism, developing thousands of sweat glands in our skin. These are launched when our brain detects the possibility that the body overheats, cooling it at the cost of expelling water. The vast majority of other mammals, however, have not exploited that possibility. Thus, dogs have a very limited ability to sweat, and almost exclusively restricted to the fence pads and the nose. Therefore, they must resort to an alternative strategy: gasp.
When your dog gasps is not to be missing from teaching her tongue; It is its main thermoregular way. Heat activates a nervous reflex that dilates blood vessels in their nose and tongue, while inducting large amounts of saliva very diluted.
A succession of rapid inspirations by the nose and expirations through the mouth help evaporate the water of the upper respiratory tract, thus cooling the blood that circulates in the area. As the process depends on a correct and synchronized respiratory system guideline, the races of brachicéfala dogs (that is, those of snorted snout, short nostril bones and reduced nostrils, such as the BulldogsBoxer or Beijing) have much greater difficulty in reducing their body temperature and running greater risk of hyperthermia.
Although removing its long tongue from the mouth increases the wet surface in contact with the air, the process is much less efficient than moistening large body areas through sweating. In addition, both strategies require an external water contribution to replace the one that has evaporated, so it is important to always provide them with an abundant source of fresh water when it is hot.
HAVE yes or hair, right?
It is common to think that we help our dogs to be cooler cutting their hair a lot in summer. Keep in mind that the fur acts as a buffer of heat exchanges between the body and the outside. While it is true that shorter hair can favor the loss of heat towards the air, heat gain also increases by irradiation of solar energy. The hair absorbs a lot of the energy of the solar rays and prevents it from reaching the skin.
Cutting a dog’s fur can cause hyperthermia when they are exposed directly to the sun, in addition to increasing the risk of developing skin cancer.
Risk of thermal shock
Dogs are quite sensitive to heat in general, although some races, such as Golden Retrieverthe farmers or the Bull Terrierthey are more than others.
Of course, as is the case between humans, puppies and advanced individual individuals, they have a higher risk of suffering a shock Thermal that endangers your life. In fact, About half of the veterinary consultations due to hyperthermia in dogs can have a fatal outcome.
A big dog problem is that, when humans want to spend time doing leisure activities with them, they get so excited that they have a hard time controlling. Therefore, we are the owners who must monitor the situation: avoid excessive activity in the hottest hours, as well as prolonged direct exhibitions to the sun.
Always have fresh water within reach of your dog, although they also usually thank a good shower or bath in time. And, of course, never, never, let a dog locked in a car, even with the semi -absert windows and for only a few minutes. If we follow these simple basic rules and apply logic, we can continue with our best friends, summer after summer, for a few more millennia.
This article was published in The conversation. Read The original.
