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Why is my dog biting her tail and back? Fleas, mites, or allergies?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed | Female | unspayed | 1 year and 9 months old | 30 lbs

Why is dog biting back tail

3 Answers

Most Helpful Answer

Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on April 19th, 2017

Poor Lola! She could be biting her back and tail because of fleas, mites, ringworm, or allergies. If she isn't up to date on her flea treatment, she will need a spot on treatment such as Advantage or Revolution. You will need to disinfect the environment as well. If she is up to date on her flea treatment, I recommend taking her into the vet for an exam tomorrow. The vet can do blood tests, skin scrapings, and use a Wood's lamp to diagnose allergies, mites, and ringworm. Once the cause of the biting is found, the vet can prescribe the appropriate treatment.

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Andrea M. Brodie, DVM
Veterinarian
Published on December 22nd, 2018
This would be a typical spot for fleas to bite and congregate, so if you have not done any flea protection you will need to start with that now. There is a possibility that your dog is suffering from a flea bite allergy, and getting rid of the fleas will alleviate that. The coughing fits/vomiting will need to be investigated by a veterinarian. This could be caused by kennel cough or another upper respiratory infection or a heart condition. I suggest you schedule an appointment with your veterinarian for an exam.
1Pet Parents found this answer helpful
Answered By Jenna Beyer, DVM, MBA, cVMA
Veterinarian, Certified Veterinary Acupuncturist
Published on October 20th, 2018
The most common reason for biting near the back legs is fleas or flea allergy dermatitis (which is an allergic reaction to flea bites). I would recommend that you have Sophie examined by the vet to see if she has flea allergy dermatitis, since she may need antibiotics or anti-inflammatories to help clear the skin while you work on preventing further fleas. She needs to be on a good quality monthly flea preventative, your vet will know which work best in your area. If it is a food allergy, just changing from one food to another may not be good enough. Some dogs need to be on a prescription hypoallergenic dog food for a couple months and then slowly add in other foods to see what she could be allergic too. Or perform allergy testing. Dogs don't often get ear mites, she may have an ear infection caused by the allergies or just feels itchy on her head.
1Pet Parents found this answer helpful

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