Why do dogs drool?

Because the sweat glands of dogs are not very developed. As long as the dog feels a little hot, it will open its mouth and stick out its tongue to gasp, and it can secrete a lot of saliva instead of sweat. Dogs evaporate saliva to give off heat and lower their body temperature. They drool a lot and absorb heat through saliva evaporation to lower their body temperature.

Other physiology of dogs:

smell

Dogs' olfactory sensitivity ranks first among all animals, and blind dogs can live like normal dogs with their noses. Dogs' acute sense of smell is mainly manifested in two aspects: first, they are sensitive to smells; The second is the ability to distinguish smells. The sensitivity will vary according to the kind of taste, which is about 1200 times that of human sense of smell. The dog's nose can distinguish about 2 million different smells, and it also has high analytical ability, and it can sniff out the smell it is looking for from many mixed smells. Dogs can perceive smells at the molecular level. For example, when 1 cubic centimeter contains 9000 butyric acid molecules, dogs can smell it, while in general, there are about 268× 10.e+ 16 molecules in the air per cubic centimeter. So the concentration of butyric acid felt by dogs is 3.36× 10.e- 17. When someone dilutes sulfuric acid by one millionth, dogs can still smell it, and their olfactory sensitivity to acidic substances is tens of thousands of times higher than that of people.

(sense of) hearing

The auditory induction can reach1.2000 Hz, which is 6 times that of human beings. The farthest listening distance is about 400 times that of human beings. Dogs are also twice as able to distinguish the direction of sound as humans, and can distinguish 32 directions. It can be distinguished that the number of times the metronome vibrates per minute is 96 or 100, 133 or 144. For human passwords and simple languages, dogs can establish conditioned reflex according to the changes of tone and syllable.

sight

Dogs' eyesight is only about three-quarters of that of humans, and among all animal species, dogs' eyesight is about medium. The dog can only see 25 degrees with one eye, so it can't see the nearest distance ahead. The lens of a dog's eyeball is relatively large and deformed like a horse's eyeball, so it is impossible to adjust the sense of distance. Twenty or thirty meters is probably its limit. Dogs have a special ability to detect moving objects; They can detect images that move 70 lines per second, while ordinary TV images move 60 lines per second. Dogs have better eyesight than people in dim light. Dogs are natural carnivores and live by hunting, so they also have considerable vision in the dark. Dogs' eyes can see short-wavelength colors. In addition, the dog's cornea is bigger, which allows more light to enter the eyes, so it is easier to see things in dim light. But in the darkness without light, dogs can't see.

tooth

Dogs have short crowns. The crowns of the first and second maxillary incisors are three-pointed, with canine teeth in the middle and small peaks on both sides. The other front teeth have two small peaks, and the canine teeth are conical and extremely sharp, which is a powerful weapon for attack and self-defense. The front teeth are three-pointed, and the Japanese teeth are multi-pointed.

intestines and stomach

The digestive tract of dogs is shorter than that of herbivores, and the hydrochloric acid content in dogs' stomachs ranks first among domestic animals. In addition, the intestinal wall is thick, the absorption capacity is strong, and it is easy to digest meat food.