Dogs always biting their tails may be due to boredom, nature, attracting the owner's attention, obsessive-compulsive disorder, skin diseases, anal adenitis, lack of trace element selenium, etc. When a dog appears in this situation, it is best to take it with him first. The dog should go to the pet hospital for examination to avoid worsening of the condition. You can play with your dog more often. If you don’t have time, prepare some more toys and teething sticks for your dog. Regularly deworm your dog, clean its anal glands, etc. to keep your dog clean and hygienic.