Why does my dog keep eating hair (its own fur)?

A dog eating hair may be caused by the following reasons: 1) Nutritional deficiency—if the dog lacks fiber, protein, vitamins, and similar nutrients, it may eat hair; 2) Anxiety or stress—changes in environment or the owner’s absence can make a dog anxious and lead to hair-eating; 3) Digestive problems—abnormal gut digestion can also trigger it.

In short, there are many reasons a dog eats hair, and you should take suitable measures based on the underlying cause.