Two Easy Ways to Start Earning Rewards!
Earn 2X Pals Rewards points at Petco
when you use Petco Pay!
Updated on September 23rd, 2025
Pet's info: Dog | Bullmastiff | Female | unspayed | 1 year and 7 months old | 90 lbs
My bull mastiff is losing her fur. Almost seems in strips. Down to the blacl skin. Started about 2 months ago. She is about 18 months old and has regular vet checkups. They cant seem to find out what is wrong with her.
4 Answers

Answered By Shaneez Wallani, DVM
Veterinarian
Published on March 25th, 2019
Answered By Dr. Elizabeth
Veterinarian
Published on July 6th, 2017
The most common reason for redness and hair loss in the lower back area is fleas. Put Nik on a flea prevention. If you can find an oral product, these typically work best. Environmental allergies or food allergies can also cause skin issues but rule out parasites first. The darker colored skin is in response to the inflammation in her skin. Typically a steroid or antihistamine can help decrease the inflammation. Talk to her veterinarian about what is the next most appropriate step.
1Pet Parents found this answer helpful
Answered By Dr. Leigh, DVM
Veterinarian
Published on December 13th, 2016
She could have a skin infection, allergies, mites, flea allergy dermatitis, etc. Your vet can do a skin scrape, cytology, and/or culture to help diagnose and then prescribe medications to treat. She may need an antibiotic, antihistamine, corticosteroid, or other medications depending on the diagnosis.
1Pet Parents found this answer helpful
Answered By Dr. Strydom, DVM
Veterinarian
Published on April 11th, 2019
This actually looks very much like a flea allergy dermatitis to me. Of course it is impossible for me to diagnose via the internet with one photo. I am all for owners trying things at home for their pet before going to the vet as long as the animal is doing otherwise well. If those home treatments are not working, then I suggest you get Riley to your vet for an exam so you can figure out what is going on and get him the appropriate treatment. Best wishes.
1Pet Parents found this answer helpful