A wolf can become a dog if the player gives it enough bones. When it becomes a dog, its color changes to brown, a collar appears on its neck, and heart particles spawn around it. If the dog is given Bone Meal, the dog's collar will switch color from red to white.
If you attack or hit a mob and a dog is not in sitting position, the dog will attack the mob until it dies, or its target changes in the middle of the fight. Shift-clicking on a dog will make it sit. In this sitting position, it cannot move or attack a mob, but it can still take damage from hostile mobs.
The dog's health can be measured by the angle of its tail. If the tail is pointing downward, it's health is low. Beware! You can actually damage your own dogs and kill them, gaining experience but losing your pet.
You may feed them food such as pork and chicken to regain their health, but you can't breed them.
If a dog gets trapped somewhere and you walk off screen, it will transport back to you in a few seconds.
Sometimes they get stuck in walls. Then they start climbing them!!!