Canine Mammary Tumors & Spaying

Last Modified: September 17, 2012


My dog has a mammary tumor and is having surgery next week. I have been advised to spay her at that time- is there a benefit to that since she already has the cancer? I have 2 1-year old pups from her- are they at higher risk with a mother with the cancer? And does spaying now reduce their risk

Erika Krick, VMD, DACVIM Veterinary Medical Oncologist, University of Pennsylvania, responds:


We generally recommend that dogs with mammary tumors be spayed at the time of tumor removal as many of these tumors are stimulated by estrogen. Dogs that are spayed before their first heat cycle, between their first and second cycles, and between their second and third heat cycles have a significantly lower risk of mammary tumors, so if you do not plan to breed the puppies, I would recommend that you have them spayed to decrease their risk.

Learn more about canine mammary tumors.

This question and answer was part of the OncoLink Brown Bag Chat Series. View the entire transcript from When a Beloved Pet has Cancer.