Does your dog bite his tail vigorously, tearing out clumps of fur?
This is not funny - this is a cry for help.
This behavior may indicate problems that can no longer be ignored, such as an allergy to flea bites.

Even one flea can cause unbearable itching, and the dog will bite itself until a wound appears. But if there are no parasites, the cause may be more serious: a tumor, a neurological disorder, or an autoimmune disease.
Often the food is to blame. Cheap brands with an excess of grains, dyes and preservatives cause dermatitis. The dog scratches itself, licks its paws, and the tail becomes a "victim" due to easy access.
Try switching your pet to a hypoallergenic food with hydrolyzed protein or a natural diet. Eliminate chicken, which is a common allergy trigger.
But there is also a psychological background. Dogs that are left alone for a long time begin to bite themselves from stress. Breeds with high intelligence suffer especially: border collies, Labradors, Dobermans.
They need not just walks, but mental stimulation. Buy puzzle toys, hide treats under overturned cups, teach new commands. A tired dog will not chew its tail - it will have no time for that.
If wounds have already appeared, treat them with chlorhexidine and put on a protective collar. But remember: this is a temporary solution. Without eliminating the cause, the problem will return.
And if there is no improvement in a week, run to the vet. Delay can cost your pet its life.