Updated On September 23rd, 2025
Pet's info: Dog | Mixed Breed Small (up to 22lb) | Female | spayed | 10 years and 9 months old | 5 lbs
Underneath my dogs tail has become red, rough, swollen, and dark. What can be causing this? (Picture attached)
1 Answer
Published on August 27th, 2017
These skin changes are from licking and probably scooting or rubbing this area on the floor. This can be from Josie's anal sacs being full causing the area to be itchy. Anal sacs are on each side of the anus, they are like scent glands in a skunk. They have a foul smelling fluid in them. Normally when a dog defecates some fluid is discharged. If the sac opening becomes clogged the fluid can build up causing pressure, itchiness and often dogs will scoot on their rears. Sometimes they get infected and the area will become red, painful and puss may rupture through the skin. Having full anal sacs is more common with small dogs like Josie. Your veterinarian can manually express the fluid and give the dog relief. Some dogs need to have their annals expressed every few months. The skin under the tail should improve once the rubbing and irritation stop. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for Josie.
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