Petco Text Logo
Petco Pet Logo
  • Two Easy Ways to Start Earning Rewards!

    rewards header
    Become a member today!
    Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
    Petco Pay LogoBecome a credit card member today!

    Earn 2X Pals Rewards points at Petco
    when you use Petco Pay!

    APPLY NOW
    Learn More About Petco Pay Benefits

My dog has a breast lump, low energy, and black stool. What's wrong?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Female | unspayed | 11 years and 10 months old

My dog has a medium size lump on her breast. She has low energy, frequent thrist and urination. She had an accident a day ago where her feces was really black. I'm really concern. We have noticed this past week of her energy change and the lump when I bathe her. Please help.

1 Answer

Most Helpful Answer

Jacqueline Nobles, DVM, DACVECC

Answered By Jacqueline Nobles, DVM, DACVECC

Veterinarian, Board-Certified Emergency/Critical Care Specialist

Published on February 18th, 2017

As for the bump, my biggest concern would be an enlarged lymph node and mammary cancer. The black stool, lethargy, and thirst are suggestive of bleeding in the intestines. Since she is not spayed, a pyometra would also be a possibility. You need to get her to a veterinarian as soon as possible for bloodwork and abdominal x-rays or ultrasound.
Vote Icon1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share

Styled arrow button