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

Signs of Dog Cancer and Decompensation

Updated: November 22nd, 2018

People are often stunned to find out their dog has cancer. Why? Because cancer seems to hit out of the blue. I often hear “but he’s been fine until the last couple days!” In this article, I’m going to take just a minute to explain why “cancer” seems to happen overnight. (Hint: it’s because of dog cancer decompensation … not cancer itself.)

“Signs of Dog Cancer” Are Really “Signs of Dog Cancer Decompensation”

Search for the warning signs of dog cancer, and you’ll find plenty of listicles that include items like the following:

  • a new lump that is hard
  • a limp
  • coughing
  • weight loss
  • loss of appetite
  • vomiting
  • diarrhea
  • thirst changes
  • bad breath
  • yellowing of the skin or eyes
  • abdominal swell
  • difficulty breathing
  • spontaneous bleeding
  • unusual odors

But those are not signs of cancer. They are signs of dog cancer decompensation.

Your dog has had cancer for a lot longer than you realize. The signs listed above are actually signs that your dog’s body has stopped being able to compensate for cancer, and her body’s normal functions are breaking down.

Looking back at your dog’s last few months, or even year, you might think I’m crazy.

How is it possible that a dog can act totally happy, eat, drink, move around, socialize … and have cancer?

Don’t sick dogs act sick? Well, let’s take a look at that.



Decompensation Defined

The clearest definition of decompensation I’ve found is this:

“Decompensation is the functional deterioration of a previously working structure or system.”

Every organ and system in the body function well under normal circumstances. And every organ is designed to have lots of built-in safety systems so that if something goes wrong, the organ can STILL function while it repairs itself.

So, when a medical problem is introduced, the body can “compensate” for it. Let’s take a non-cancer example.

Say you are using a hammer and hit your thumb. That’s our medical problem: your bruised thumb.

The tissues immediately swell up. That’s the immune system sending fluid to the area both to keep it from moving too much (which could further injure it), and also to bring white blood cells to the area to start helping repair the damage.

Your immune system is “compensating” for the medical problem by sending help.

Now, normally, your thumb would heal in a few days or a week. You might not even really notice the thumb’s hurt, after a while.

But let’s say that you damaged your nail very badly in the strike. The body simply can’t repair the damage done. After a week or so, you might find your nail falling off. Now it takes months for your nail to grow back in.

Well, that’s your “decompensation,” right there. Normally, you have a nail on your thumb. But now, you don’t. Your body could not compensate for all the damage done.

So now you’ve got a clear sign … for months … that you have been damaged, and that things aren’t normal.

When Safety Systems Fail

When your dog has cancer, her body will kick in all sorts of safety mechanisms (depending upon where the tumor is) to keep the body working properly. Dogs act normally during this time.

So do people, if you think about it. You probably know someone who has had cancer. Did they feel terrible right at the beginning? No … we don’t start really noticing symptoms until cancer has disrupted our health. Until our safety systems start failing.

So what we see listed as the “signs of cancer” are not really signs of cancer at all. They are signs that cancer has gone past a certain tipping point.

They are signs of dog cancer decompensation.

They are signs that cancer is in a late stage.

In other words, once a dog starts to act sick, it’s already late in the game.

What to Do If Your Dog is in Decompensation

If your chest is tightening as you realize that your dog isn’t “suddenly sick,” but may have had cancer for a while, please take a few deep breaths.

This is a difficult concept to accept, and it’s totally normal to feel, well, to feel awful about it. Just because we usually find cancer late (after decompensation) doesn’t mean that we can’t do anything about it. There are lots of things to do to help your dog’s life quality and even optimize longevity.

So if you haven’t had a diagnosis yet, get one. Knowing what you’re dealing with will help you to make decisions. And if you do know it’s cancer, don’t be afraid to get a second opinion, just to make sure. Any professional vet will be okay with this, and it wise to double check to make sure the dog cancer journey is a path you are on.


Get the Dog Cancer Survival Guide to read more on End of Life and Hospice Care, in Chapter 25


Bottom Line: Test Healthy Dogs for Cancer

The fact is that one out of two dogs over ten gets cancer, and one out of three overall get cancer. It’s the number one killer of dogs at this point. So we should all be taking it very seriously, and testing dogs for cancer, earlier, when they seem healthy.

Starting in the last quarter of life at the earliest, get annual (or more frequent) imaging done to look at internal organs: X-rays, ultrasounds, etc. Don’t ignore lumps and bumps, but get fine needle aspirates, biopsies. Blood and urine tests can serve as critical screening tools.

When’s the last quarter of life? There’s a comprehensive list in my book for breeds and their average life expectancy, but you can also base it on weight:

  • Dogs up to 12 pounds live approximately 14 years, so start annual testing no later than 10.5 years.
  • Dogs 12-30 pounds live approximately 13 years, so start annual testing no later than 9.75 years.
  • Dogs 31-50 pounds live approximately 12 years, so start annual testing no later than 9 years.
  • Dogs 51-80 pounds live approximately 11 years, so start annual testing no later than 8.25 years.
  • Dogs over 80 pounds live approximately 9 years, so start annual testing no later than 6.75 years.

The reality is that when caught early, cancer is easier to treat and we have better chances of preserving life quality (and even extending longevity).

Best to all,

Dr D



 

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  1. nh.hiker on September 4, 2012 at 6:14 pm

    Our 12 year old lab passed on this night. 3 weeks ago she had a slight limp on the back right. Vet gave her some pain meds and said if she didn’t feel better in a few days, we should xray. also said its not uncommon for labs her age to have cancer and a bone break can be an indication She seemed to recover 100 % and was doing well.. this afternoon she slipped on the floor. The ER vet took xrays and she had a clean break of the femur. At first they talked about surgery and plating the break. The poor girl had endured two TPO’s on her hips at 7 months and a TPLO on her left knee at 9 years and thrived. Weve been crossing our fingers on the last knee staying healthy. When they xrayed and said it could be plateable we were overjoyed on to then have the chest xray done that showed advanced cancer. they gave her 2 months without the break which was not going to be fixed now. we know we had longer than we should with a Yellow with so much osteo trouble. She had a good 12 years and we will miss her much longer than that

  2. ES on August 20, 2012 at 7:52 pm

    To everyone that has a dog fighting cancer, I highly recommend K9 Immunity Plus. They are flavored wafers that you feed your dog 1-3 times a day, depending on the size of your pet. My dog was diagnosed with bone cancer in early May once we noticed his leg has swelled up and he was limping. I immediately researched and bought the supplements. So far he is doing well! We opted for no surgery or chemo since he is 12 years old and chemo weakens the immune system. We also have him on a grain-free diet and are using the Taste of the Wild brand. I researched and learned that without surgery, dogs with bone cancer live 1-2 months but my dog is entering his fourth month and is still full of energy, plays with his toys and loves to eat. I don’t know what tomorrow will bring but I believe these supplements are helping keep my dog with me and everyday is an extra day that we get to spend with him.

  3. kcarabello on July 25, 2012 at 6:59 pm

    Thank you Dr. D, I appreciated it.

  4. kcarabello on July 20, 2012 at 5:07 pm

    A few days ago I, also, had to put my lab to sleep. It was the hardest decision I ever had to make. He would have been 12 in a few days. I feel so guilty, even though, I know it was the right decision. He hardly could have walk and always he always sounded like he had to cough. He had a hard time barking the last few days. He woke up one morning and started throwing up and collapsing and couldn’t catch his breath, we rushed him to the vet, at that time his tongue was blue, they game him a steroid shot, and took x-rays and his lungs were full of cancer and she believed his hard time walking was due to cancer. We were treating him for arthrisis. I know it probably was the best gift we could of given him to make him no longer suffer, however, It is so hard. He is all I think about and wonder if there was anything else I could have done. Even at the very end, he was kissing and cuddling with me. I look back at the last few weeks and realize he wasn’t feeling well, like trouble barking, walking, and sometimes crying thru the night, we tried everything for him. But the pain and guilt are unreal. We loved him so much 🙁

    • Dr. Demian Dressler on July 24, 2012 at 8:54 pm

      Dear Kcarabello
      A little video maybe that might help for you:

      Best
      Dr D

  5. mrogers on July 18, 2012 at 6:16 pm

    You are right about cancer suddenly seeming to appear. Our beautiful 9 year old yellow Lab seemed fine until 3 weeks before we had to have him put to sleep. He was getting thinner and his back legs were shaky, and he was always such a big strong muscley boy. He was diagnosed with a liver tumor and a week later he could keep no food down or water. We had to make the decision not to have him suffer and starve to death in front of us. Afterward our vet felt another larger tumor in his stomach which must have grown enough to prevent digestion in just a few days. We thought we would have him at least a few years longer. We miss him so much! We are thankful he didn’t seem to suffer more than those last few days and we could all be around him and care for him that week.

  6. Ruthie Orndorff on July 5, 2012 at 1:49 pm

    Our 7 1/2 has a 2inch tumor it is cancer I started giving her Omega 3,6,9 and Vita c
    d,e she is in no pain I took her off her diet because she lost 10 pounds in 3 months
    so I gave her back her 1 cup and just not alot of people food she is eating Squash, and green beans she is happy no pain and is feeling better can she make it my husband will not go in debt over our dog she is on her own for getting well and no steroids marty said it’s a band aide. is that ok

    • Dr. Demian Dressler on July 10, 2012 at 10:00 pm

      Dear Ruthie,
      I am sorry about your dog. I am not quite sure, though, what the question is. Are you asking if prednisone is okay? It can be okay…everything has both desired effects and also side effects (not desired). I might be thinking of some of the other steps in the Guide- Apocaps, Neoplasene, and others…
      Dr D

  7. aJ on April 13, 2012 at 4:22 am

    Do lots of spindle cells in a growth always mean cancer ? the vet did a needle biopsy and looked at it under the microscope yesterday and said he could see lots of spindle cells but they could turn into any type of tissue and be harmless, so he couldnt say what it was but advised having the lump removed within 2 weeks and sending it away to see if she should have chemo, he wouldnt say any more until the biopsy comes back.

    I think he was trying to not scare me too much but it has left me a bit confused as nothing i’ve read about spindle cells has been good

  8. nicole on April 2, 2012 at 7:30 pm

    my 11 year old dog a 140 pound lab just had this diagnosed through needle aspiration! Spindle cell Sarcoma he has another lump om right shoulder a week later almost same size it is ridiculous 🙁 It seems aggressive and fast and he is 11 and huge we are just feeding him steaks and taking a ton of walks! I am giving my dog that surgeon said he can not help the best last few months. it is hard and i keep sleeping on floor every night while my boy has the couch but I am not going to put him through unnecessary treatment to make myself feel better!

  9. Gloria Alexander on November 27, 2011 at 10:25 am

    In 2010 I wrote above about my dogs battle with Bladder cancer and that she had recoved and was cancer free. (Carboplatin/Piroxicam, 5-6 Omega 3 caps. daily) raw diet, but now I read raw is not good for dogs w/cancer.

    Unfortunately 1 year ago she got a melanoma on her tongue and had to have surgery, and with clean margins was put onthe “vaccine” Protocol. Due to my financial inability to continue with the “every 6 month” vaccine the cancer came back with a vengence. She has lumps every where. Xrays show she has 3 tumors in her lungs.Today she has begun to cough….
    She received the vaccine, which is suppose to boost the immune system. Then she was put on Palladia, for almost 2 weeks, showing no improvement. Now her oncologist gave her the first Carpoplatin treatment on Monday and this Monday, one week later, I am to continue with the Palladia.
    Dr. Dressler, please tell me what protocol you recommend as far as the chemo is concerned. What really is the drug of choice. I know I am losing my best friend, but I don’t want her to suffer. I think the chemo has effected her appetite this time. She seems to only want to eat liverwurst, I use that to put her fish caps in.

  10. Sara on November 17, 2010 at 6:43 pm

    Our sweet yellow lab Ben was diagnosed with what we believe to be hemangiosarcoma. He was seen at the vet in April due to lethargy, not eating and just “not acing himself” for one day. One day. Bloodwork showed low platelet levels, abdominal xray showed a very large tumor on his spleen and another large growth near the liver. I was not at all prepared for this. At 11.5 we decided not to do surgery, I scoured the internet and learned that 2/3 of splenic masses in large breed dogs were sarcoma and that surgery offered a mean survival of 1-3 months. It was a gutwrenching decision not to do surgery. We had another 6 months w/ him – he passed peacefully on October 30. Not sure why I’m posting other than to share Ben’s story and learn as much as I can about canine cancer. He left us too soon. I’m struggling with grief and guilt…missing my best friend.

    • DemianDressler on November 23, 2010 at 6:21 pm

      Dear Sara,
      so sorry to hear this sad news. Thinking of you.
      D

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