1, see if there is a "flower tongue"
There is a saying in "Pick a Dog" that "a good dog opens his mouth to see a colorful tongue", which means that a dog with a colorful tongue is a good dog. They are in good health and are not easy to get sick. Such a dog is easy to feed, free of cost and worth keeping.
2. See if there is a "tile nose"
Dogs with wagging noses usually mean that they have a keen sense of smell. It is a blessing to have such a good dog in an era when hunting is needed. Such dogs are also very good now. If something unusual happens at home, such as a gas leak, the dog will smell it immediately and remind the owner.
3, the dog's tail "vertical middle"
A good dog should not be too timid. Dogs that often hide their tails between their legs, pick them up or drag them down, are not easy to keep at home. The watchdog has to carry a heavy burden, that is, a "brave dog" with its tail straight in the middle of its body.
4. Lift the dog up and observe its reaction.
If you want to choose a smart and bold dog, you can pinch the dog's back neck, let the dog off the ground and see its reaction. If the dog hunches over and looks at you warily, it means that the dog is brave. Tame it and you can use it.