Cold knowledge about dogs

The cold knowledge about dogs is as follows:

1. There are seven blood types of dogs.

2. Every dog's nose print is as unique as human fingerprints.

3. Dogs have no sweat glands, but their sweat glands are distributed on the tongue and claws.

4. Dogs lift their legs to urinate, not to be clean, but to show dominance.

5. Dogs have night vision.

6. An untrained dog will watch you go out and wait for you to go home as long as it recognizes you.

7. The longer the dog's nose, the less likely it is to get heatstroke.

8. The dog's world is not black or white, and they can also see blue and yellow.

9. A dog wagging its tail is not necessarily happy.

1. The dog's sense of smell is 1 times that of human beings, and no smell can escape its nose.

11. Puppies and dogs grow up by sleeping, so don't worry about starving them.

12. Dogs are descended from wolves.

13. The dog's wet nose is to keep its sense of smell better.

14. A dog's teeth are not necessarily angry, but may be happy, provided that it is relaxed.