There may be many reasons why a dog bites his tail. Here are some possible causes, pain or discomfort. Dogs may bite their tails due to pain, swelling, insect bites, etc. in the tail area. Anxiety or stress. Dogs may bite their tails due to emotional problems such as stress, loneliness, and separation anxiety.
Disease or parasitic infection. Dogs may bite their tails due to physical discomfort or parasite infection. Trying to attract the attention of the owner or other dogs. Some dogs will bite their tails to attract the attention of people or other dogs around them. If your dog bites his tail frequently and strongly, it is recommended to take him to the veterinarian to rule out physical illness or other health problems.