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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Breast Cancer Signs in Dogs: What to Look For and How to Think About Mammary Cancer

Updated: December 16th, 2019

Summary

Finding a lump on your dog’s breast is not good: Learn how to examine your dog for breast cancer and when to head to the veterinarian.

Breast cancer … in dogs? Can dogs even get breast cancer? Yes, they do.  We don’t call it by the same name; in dogs, we call it mammary cancer. But because the mammary gland is the bulk of the breast, and the disease is very similar, mammary cancer is, in fact, dog breast cancer.

Thankfully, breast cancer in dogs is not as aggressive as breast cancer usually is in humans … but it’s serious, nonetheless. For a full discussion of breast cancer, including its warning signs, treatment, and special diet considerations, please see chapter 31, which starts on page 320 of The Dog Cancer Survival Guide.

Signs of Breast Cancer in Dogs

Signs of breast cancer in dogs include the following:

  • small nodules (bumps) within the mammary tissue that feel like little BBs under your fingers
  • larger nodules within the mammary tissue, still under the skin
  • bloody discharge from the nipple
  • straw-colored discharge from the nipple
  • pus-like discharge from the nipple
  • larger, deeper growths in the mammary tissue that protrude visibly and can be seen as lumps

Want to learn more about mammary tumors and how to treat them? Get the Dog Cancer Survival Guide, and flip to Chapter 31


Spaying and Breast Cancer

Veterinarians often advocate early spay for females because it can prevent breast cancer later on. This is usually done before the first heat comes at about six months.

And it’s true: female dogs who have been surgically sterilized before their first heat, which is usually around 6 months of age, usually live essentially free of breast cancer.

As the spay age increases, this protection drops.

Sounds good, right? Well, yes, as far as breast cancer goes. But you should also know this: early spay and neuter before the first heat is associated with increased risks of other types of cancer.  Those other types include the very aggressive osteosarcoma and transitional cell carcinoma.

This is why we debate whether early spays help avoid cancer. The evidence is mixed. Early spays almost completely eliminate breast cancer, which is nice. But early spays INCREASE the risk of more aggressive cancers.

Found a Lump on Your Dog’s Breast? Get It Checked.

The most critical thing to remember is that if you have a female dog who has a bump in the area around the teat (nipple), please get it checked.

Many of these growths are life-threatening.  And if you have a female dog who is not spayed (intact), or was spayed later in life (at more than 6 months of age), examination of the mammary tissue of your dog may be a lifesaver.



How To Give Your Dog a Home Breast Exam

A breast exam in dogs? Yes, you heard it here first.  You should absolutely examine your dog, especially if she is intact or spayed late.

How do you do it?

First, you have to be able to see and feel her belly. Many dogs already like to lay on their sides or back.  If your dog “gives belly,” you can do her exam then … but even dogs who won’t roll over can still be examined.

Whether giving belly or standing up, here’s what you do.

First, find the mammary glands. Dogs normally have ten, two rows of 5 going down the length of the body, one on the left and one on the right. If your dog has an extra teat or a missing teat, or if they are not perfectly aligned from left to right, don’t worry. Variations are normal!

Second, use your fingers to “see” as well as feel, as instructed below. There are two separate techniques to use — so don’t skip these steps.

  • To make sure your dog is comfortable, try doing this with two hands, one on the left chain and the other on the right chain.
  • Keep your fingers flat and use the pads of your fingertips to “fan” through the mammary tissue up and down the torso, from the head to tail. Start on the first teat on both sides and work down toward the last teat on both sides, feeling for “blips” or bumps under your fingertips.
  • Still keeping your fingers flat, fan your fingers left to right, from the first set of teats to the last. You are still looking for those little blips or bumps.
  • Next, use the second technique, which is to gently press the mammary tissue to look for deeper bumps or lumps. On each teat, gently gather the mammary tissue between your thumb on one side and your index and middle finger on the other. Keep in mind that this could be sensitive tissue, so be gentle! Gently roll the tissue with your thumb as your fingers hold the other side. Move your thumb in a circular motion and feel for blips and bumps between your fingers.
  • Remember, you are looking for little lumps and nodules that feel different from the surrounding mammary glands.
  • Any area that is hard or different is worth having a veterinarian take a look at.
  • If you can see pus, blood, or any other abnormality on the mammary tissue, get it looked at.

How often to do an examination like this on your dog?  I suggest every month or so for female dogs above the age of 7 years.

Even if your dog had an early spay, do a breast exam every once in a while for your own peace of mind. It’s well worth the few minutes.

Treating Breast Cancer in Dogs

Breast cancer in dogs is best treated with a combination of different Full Spectrum steps.  In my patients, I use surgery, dietary changes, Apocaps, deliberate efforts to increase life quality, reduction in body fat (a risk factor for mammary cancer), immune-boosting and anti-metastatic supplements, touch therapies, and more.  As a rule, this cancer does not respond very well to chemotherapy.

Best,

Dr D



Spay/neuter and the association with cancer in dogs: part one

Leave a Comment





  1. Rebecca on September 24, 2017 at 8:50 pm

    I’m worried about my dog found a hard stone/lump in one nipple and it’s leaking, could this be cancer?

  2. Susan Kazara Harper on May 17, 2015 at 11:05 pm

    Hello, Your dog’s priority right now is the litter, and the task and joy of the pups. For now please get her nutrition as fantastic as possible; check out the Dog Cancer Diet for the best real foods to move her onto, and the foods to avoid, just in case she is dealing with cancer. The pups will not be affected, and nursing won’t be a problems as far as a possible cancer diagnosis goes. As soon as your vet can do it, getting a biopsy should be pretty easy…. work with the vet and take it from there. It’s easy to worry, but it doesn’t help anything. Stay vigilant, love her and give her all the support she needs. Good luck!

  3. florescanineservices on May 3, 2015 at 1:26 am

    Vet said most likely breast cancer, but, dog is pregnant, 4 to 5 weeks, best course of action to take to try and save the litter? Cannot afford expensive treatment, may be best to let nature take it’s course and hope for the best?

    In the 40 plus years of Vet work, Dr has not had to deal with this particular scenario,,,

    Thanks in advance for your input

  4. Elizabeth on March 25, 2015 at 10:29 am

    My four year old pit bull has a swollen mammory gland or lymph node where her thigh meets her abdomen. A few months ago, she had really bad swollen lymph nodes on the back of her neck and under her chin. She was given an antibiotic and the swelling went down after a few weeks. I’m concerned that she has a lymph node cancer of sorts. If it was just an infection, it shouldn’t have returned, right? Another bit of information, she broke her paw a few days ago. My veterinarian didn’t set it because he said it would heal better and with more movement without a cast. He gave her an antibiotic.

    • Susan Kazara Harper on April 13, 2015 at 4:18 pm

      Dear Elizabeth, Please forgive the delay responding .. we’re doing our best to keep up. Swollen areas are scary when you are as aware and conscientious as you are with your girl. Getting her sorted with the vet was the best course of action, and the best thing now is to stay on top of it. While swollen glands can be a sign of cancer, they aren’t always. With such a young girl, this is when you would just stay aware. If any swollen areas return, it would be a good idea to ask to have at least a needle aspirate of one or more of the glands. That is the first, easiest test to check the fluid for any cancer cells. Some vets will resist testing if that is the only symptom, but you’re her mom and you’re in charge 🙂 . In the meantime, please don’t spend your days worrying, it doesn’t help either of you. Using the information in thie forum to get her onto the best nutrition you can (no cheap, commercial foods, etc.) will help keep her immune system strong. If you find any other areas of swelling, make an appt and get them checked out. Even if it is a result we don’t want, early detection is vital. You may want to check out the Dog Cancer Diet. There’s a link at the top, right of this blogpage, or you can go to http://www.dogcancerdiet.com for a free download. You don’t have a cancer diagnosis, but the diet is packed with information about good, nutritional choices for your dog which can help. Also, the site http://www.dogcancershop.com has some real quality commercial foods that will help your girl stay young and vital without exposing her to ingredients which cheaper brands use, and which are no good for our pups. And…. (there’s always more) EverPup would be a perfect choice for her. It’s a wonderful nutraceutical to add to her diet, and it contains some of the ingredients Dr Dressler recommends for dogs to stave off cancer cells. It’s designed for healthy adult dogs. http://www.everpup.com or http://www.everpupclub.com has all the information you may want. Please give your precious girl a big hug from all of us. You’re being a wonderful Dog Mom, and I know she knows it! Good luck!

  5. Susan Kazara Harper on January 5, 2015 at 9:47 pm

    Hi, We have no evidence that there is any danger to the pups from their mother’s milk, even though she has mammary cancer. And the benefit to her of nurturing them will undoubtedly do her some good as well. Good luck.

  6. Snowie on December 25, 2014 at 3:37 am

    Can she feed her puppies if she has mammary cancer?

  7. Susan Kazara Harper on December 7, 2014 at 10:30 am

    Hi Lewis,
    Best thing to do is to get her to the vet. No one should attempt to diagnose online, yet we’re here for you once you know what you’re dealing with. We always do recommend getting all lumps and bumps checked without “waiting to see”. As to whether cancer can be diagnosed without surgery, there are ways. Many vets with a lot of experience can give you a good idea, but without at least a needle biopsy, where they draw out cells from a mass and put them under the microscope, it’s difficult to say for certain. You would also need to know the type of stage of any cancer to determine a treatment plan. This cannot be done without getting cells through a needle or a small piece of tissue being taken. Do let us know if there is further informaton now, and if we can help you untangle any of it. All the best.

  8. Lewis on November 21, 2014 at 11:45 am

    Hi I have a 4 year old pitbull not spayed I have just found a group of lumps next to her front nipples the size of small poly balls her behaviour hasn’t changed and in general she seems fine just wanted some more info on it as I am really worried she is like my baby plz help

  9. Susan Kazara Harper on October 27, 2014 at 6:30 pm

    Hi Aaron,
    Well done for finding these differences.
    It would be irresponsible to offer an opinion online for your girl, and at best would be only speculation anyway. You’re doing the best thing by making that vet appointment. Don’t delay. Good luck.

  10. Aaron Smith on October 25, 2014 at 2:46 am

    Hi,

    i noticed this morning when giving my 3 year old boxer bitch a belly rub that one of her teats was wet. on futher inspection i tried gently massaging them…a pearlecent liquid came out of them. this was the same for 2 or 3 and then on one of her smaller teats there was blood…not alot but mixed in to the semi clear liquid. she has no lumps in the breast tissue as you advised i examined her that way… the breast tissue around the lower teats are puffier though as if she has fat sorrounding the teats which isnt lumpy just fatty as it rolls through the fingers. The isnt an over weight dog and is generally lean on her stomach… we will take her to the vets but just wondered what you initial thoughts would be… thanks in advance

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