You Make The Diagnosis: Dermatitis on a Dog’s Rear End

Recently, I saw a male/neutered dog who suddenly started licking his rear end.  His family noticed a lump on the left side of the anus three days before they brought him in.  Now the lump is gone but the dog is still licking.  They did not notice any other abnormal behavior.  He is eating, drinking, urinating and defecating normally.  What is wrong with this dog?  I am holding the dog’s tail up for this picture to give a good view of the his anus.  (I apologize for the fuzziness in this image.  My camera seemed to have a mind of its own for this shot.)

Diagnosis:  Anal Gland Abscess

Dogs have two scent glands located just inside the anus which are called anal glands.  These glands are actually sacs that secrete a smelly substance.  Each gland has a small opening on the edge of the anus, usually about the 4 and 8 o’clock position.  During defecation, the secretion is squeezed on to the feces.  In this dog, a plug developed at the opening to the gland which prevented the sac from emptying.  Over time, the secretions changed from a greenish, yellowish watery material to thick black sludge.  An infection developed within the gland causing the swelling described by the family.  Eventually, the gland ruptured releasing the contents and the dog licked to clean it up.  With proper treatment, most dogs who suffer from this condition will make a full recovery.  I emptied this dog’s glands, cleaned up his rear end and sent him home with 1) an e-collar to prevent licking, 2) antibiotics for the infection, 3) medication to control his pain and 4) instructions on how to care for the wound at home.    

Anal gland abscesses are fairly common in dogs.  If your dog is scooting, seems painful or is licking their rear end more than normal, please get their anal glands checked right away.  Regular emptying will prevent this condition. 


Published by kristennelsondvm

Dr. Kristen Nelson grew up on a farm in Watertown, Minn., where she developed a deep love for animals of all kinds. She received a Doctor of Veterinary Medicine degree from the University of Minnesota, College of Veterinary Medicine. Kris then completed a small-animal internship at the prestigious Animal Medical Center in New York City. In addition to writing and speaking, she cares for small and exotic animals in Scottsdale, Az. Dr. Nelson is widely quoted in the media. Her credits include Ladies’ Home Journal, USA TODAY, the Los Angeles Times and numerous radio and television interviews. Dr. Nelson has written two books, Coated With Fur: A Vet’s Life and Coated With Fur: A Blind Cat’s Love. Kris and her husband Steve share their home with rescued cats, birds and a dog.