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My female dog has a lump on her breast. Is it mammary cancer?

Updated on September 23rd, 2025

Pet's info: Dog | American Bully | Female | unspayed | 6 years and 9 months old | 55 lbs

Hi: my name is Denise my fluffy daughter Moet Williams she has a big lump in one of her breast can you tell me what it may be Thank You Denise Williams

3 Answers

Most Helpful Answer

Answered By Linda G, MS, DVM

Veterinarian

Published on August 8th, 2020

Hello. The most likely cause for the lump on Moet is mammary cancer. You do want to have your veterinarian examine Moet as soon as possible & schedule her for surgery. Fortunately, breast cancer in dogs is not as aggressive as it is in women, so removing the tumor may be be curative for this site. Unfortunately, other tumors can turn up in other parts of the mammary chain, so you may want to discuss any follow up chemotherapy after the tumor has been analyzed by a pathologist. Sorry for some bad news, but I am glad you are looking for information. The sooner you address this, the better things will be for Moet. Good luck & thanks for contacting Petco Pet Education Center, formerly Petcoach.

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Dr. Dayna, DVM, CVA
Veterinarian, Certified Veterinary Acupuncturist
Published on October 12th, 2017
Unspayed female dogs are very prone to mammay masses. About 50% of these are benign and 50% can be malignant. I would recommend having the mass removed and have her spayed at the same time. Good luck and I hope she does well! Thank you for using Pet Coach.
1Pet Parents found this answer helpful
Answered By Mara Howard, DVM
Veterinarian
Published on March 26th, 2019
Thanks for using Petco Pet Education Center, formerly Petcoach! I’m sorry to hear Maxi has a mammary gland mass. Mammary masses in intact dogs can be due to a variety of reasons, including hyperplasia (an overgrowth of mammary tissue), a fatty deposit, or a cancer, among others. Ideally it should be removed and tested to know what it is, so that any treatment she may need could be determined. I would recommend discussing with your regular veterinarian what your options are. Good luck!
1Pet Parents found this answer helpful

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