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

A Sign of Dog Cancer to Know About

Updated: October 10th, 2018

What are the signs of dog cancer?

That’s a tough question.  There are internal cancers and there are external cancers.

With the external cancers, those that are found in the skin, the space under the skin, superficial muscles, or in bony structures that are close to the outside of the body, many times we see a lump.

(Find a lump on your dog? Get it checked ASAP!)

Sometimes external cancers can show up as an ulcer that does not heal. Other times it can look more like an infection, but the antibiotics just don’t clear the problem up.

But what about the internal cancers?

This is where things get rough.  It is hard to look at a loved dog and say whether there is an internal cancer.  We have many organs that can be affected. As a matter of fact, pretty much every organ in the body can be afflicted by this number one health problem of dogs.

With this fact in mind,  it might be worth while using some computer monitor space on a couple of blog posts, and look at signs of internal organ disease.  This way you can develop a framework that may be able to help you identify important changes in your dog.

In The Dog Cancer Survival Guide, we look at the signs of each of the common types of cancer. Here, we’ll go in reverse, where we look at what we might see in a canine family member and see if we can pinpoint the diseased organ.

Let’s start with an oddball, but one that we do see from time to time, and one that is easily mistaken for other medical issues.

Here’s how it looks in a dog:

Most commonly this will be a big dog, over about 45 lbs give or take.  German Shepherd, Golden Retriever, Schnauzer..something like that.

You might notice that your dog gets a little weak in the hind end.  This shows up like a bit of wobbliness, or staggering perhaps.  And it kicks in suddenly, no gradual onset.

This weakness can also show up as a sudden difficulty getting up after laying down. Or maybe sudden collapsing on the rear.

If someone were to check the gum color, it might be noticed that the gums looked very pale during this weak episode.  Next, after a short while, maybe a day or so, suddenly it goes away.

Look at the gums then, and they are pink once again.

Most of the time this is chalked up as a little stiffness, some orthopedic issue or other.  And most times, this would likely be a correct assumption.

But then the problem happens again.  Weakness, sudden onset. Wobbly back end or even collapsing.

What is going on here?

Well, this is one of the classic presentations of a bleeding tumor in the spleen, most commonly hemangiosarcoma.  This is a very aggressive, malignant tumor. There is a new treatment vaccine that may show some promise on the conventional front in development at Colorado State.

(I have seen encouraging life quality improvements and outcomes with  The Full Spectrum Plan and Apocaps in some of these patients.)

But how does this work?  How do these tumors in the spleen make a dog behave this way?

Well, the short story is that they bleed. These cancers grow out of the wall of blood vessels, and so often they are filled with blood. Incidentally, these cancers can show up under the skin as a soft or squishy feeling mass, which is sometimes mistaken for a benign fatty tumor. They feel soft because the blood within the swelling is squishy.

This is a good reason to get soft lumps checked.

Anyway, when the tumor bleeds, there is internal blood loss within the abdomen.  At this time, the dog gets weak and wobbly. The gums look very pale.  Now you can see how it makes a lot of sense.

The amazing thing is that the body is able to take the pooling blood and draw it back into the circulation.  This is called autotranfusion here.

When autotransfusion occurs, these dogs get strong again.  The hole in the tumor temporarily seals.  The gums get pink again. And the problem seems to just take care of itself.

At least, until the next time.

If you have a dog getting wobbly in the rear end, please bring your dog to the vet.  Yes, it could be the hips, or the back, but it could also be a whole slew of other things.  And one of these is a bleeding tumor in the spleen.


Dr D

Discover the Full Spectrum Approach to Dog Cancer

Leave a Comment

  1. Kelly Jo Ferry on January 14, 2019 at 3:07 pm

    I have a male 12yr old wolf hybred. Got him at a very young age, and he has always been our happy little clown. As a pup, he had health problems that were treated promptly (a pinky tip size hernia from his navel, and a prolapsed rectum). Other than this, he has been very healthy. About 4yrs ago, we noticed he was getting some lumps on his body. These are located near his back shoulder blade area, on the side of his lower abdomen, the neck area and, a growth has been growing out from under his upper eyelid. None of these things seemed to bother him and, he (up until very recently) continued to play, jump and prance like his puppy days. About a month ago, he was a little wobbly with his walking, but we assumed it was because he had just been diagnosed with an ear infection, which we treated as directed by the vet. At this time Micah also had a hematoma on his earflap, which healed into a cauliflower ear. After treating him with his meds, he seemed okay but not 100%.Currently he has been deteriorating very suddenly. Both eyes have a thick mucous and, he has lost complete use of his hind quarters. He cannot stand or walk on his own. I am heart broken and, I just dont know what to do. I work full time, but since the fires in our town, we are just living day to day in a motorhome. The house was lost in the firestorms. Any ideas or suggestions are welcome. I am desperate to find out how I can help my boy in any way I can. I love him so much. Thank you. Kelly Jo Ferry.

    • Dog Cancer Vet Team on January 15, 2019 at 8:45 am

      Helly Kelly,

      Thanks for writing, and for sharing your story with us. We’re not veterinarians here in customer support, so we can’t offer you medical advice. However, we can provide you with information based off Dr. Dressler’s and Dr. Sue’s writings 🙂

      As Dr. Sue writes in the article below, if a lump is 1cm or larger, or has been there for over a month, get it checked by a vet ASAP. This might mean getting a fine needle aspirate (or a biopsy in some cases) to determine what the lump is– it’s better to know sooner rather than later. Here’s the link to the article where Dr. Sue goes into more detail on this: https://www.dogcancerblog.com/articles/bump-lump/lumps-on-dogs-when-to-get-them-checked-by-a-veterinarian/

      Deciding on a treatment plan for your dog can be difficult. Consult with your vet, or oncologist, and find out what options they recommend, as they know you, and your dog the best. From there, you will be able to decide what treatment options YOU think would be best for your boy. Do you think he can handle chemo, surgery, or radiation? Are you willing to handle the side-effects? How important is life-quality to you? Those are just some of the things that you will have to take into consideration when making your decision.

      Here are some articles that you may find helpful in making a decision for your girl:

    • How to make decisions about Dog Cancer Treatments
    • Why your personality is so important to your dog with Cancer
    • As Dr. D writes in the Dog Cancer Survival Guide, there are many things that you can do to help your dog with cancer, such as conventional treatments (chemo, surgery, or radiation), diet, nutraceuticals, mind-body strategies and immune system boosters and anti-metastatics. Here’s a link to the Dog Cancer Diet PDF that readers of the blog can get for free : https://store.dogcancerblog.com/products/the-dog-cancer-diet

      There are many things that make a dog’s life great, from their perspective, and Dr. Dressler created a Joys of Life scale to help readers determine their dog’s quality of life. You can find out more on life quality in the articles below :

      If you’d like to try some mind-body strategies, Molly wrote an amazing article on Magical Thinking and Dog Cancer that you may find helpful! 🙂

      Consult with your vet. They will be able to perform a fine needle aspirate, and recommend a treatment plan for your dog. They will also be able to provide you with some suggestions on your dog’s other signs and symptoms 🙂

      We hope this helps!

  • Eleanor gallacher on November 16, 2018 at 8:32 am

    My dog has lost weight also his face is getting thin .. he has diareaha about twice a day . He’s not lost his appetite. His bag legs a very week he finds it hard to put weight on his bag legs to poo. He’d been on steroids for11 year because if an allegy. He’d going deaf but I font know when to put him to sleep could you advice me please.

  • Kimberly on October 1, 2018 at 4:45 pm

    Evening, I have a female 6 yrs bluehealer, Gracie, i have just found a soft to touch knot on her lower breast area. She is coming in and I heave not had her spade but plan to cause she is just not having none of that, so. I’m afraid of what it could be. She active eating well like I said I just have found it could it be related with her coming in heat?
    Thank you for help

  • Susan Kazara Harper on February 22, 2015 at 4:42 pm

    Hi Michelle, I’m sorry this reply has taken so long. What is the situation with your dog now?

  • Michelle on January 31, 2015 at 12:36 pm

    I have a German Shepard blue heeler mix who is 13. I have noticed a lump on his hind end and thought maybe matted hair at first… in the last week it has become bigger than a soft ball. It doesn’t hurt him when I touch it but he does not walk for very long. And he eats laying down. I’m afraid I’m gonna have to put him down but wanted to know if maybe it could be a cyst

  • KRae on January 11, 2014 at 4:32 pm

    Max had weak hind end, collapse, wobbly episodes twice, about 10 days apart. That was several months ago. 2 1/2 weeks ago he had a mast cell tumor, which grew to about the size of a quarter in 10 days, removed from his thigh (grade 2). Today a very small lump on his head, which appeared over 5 days, was aspirated and determined to have a few mast cells which will be surgically removed and biopsied next Wednesday. So my question is: what is done to diagnose an internal cancer that may now be appearing as an external cancer?
    Thank you so much! (Max’s person)

  • divya on April 18, 2012 at 11:59 pm

    my dog is suffering from cancer and her age 13 yrs.. doctor said operation is bit risky and she may also it-seems i’ am worried about that.. as she is too old for operation and she cant bear the pain also.. please suggest me any home medicine for her and she is not eating her food also…

  • Yash on March 8, 2011 at 3:49 pm


    My GSD got very ill a week ago. He had diarrhea for 8 days, vomiting for 3 days and then all of a sudden started getting very weak. He didn’t even want to go outside for walks, which was so abnormal because he was usually the first one to the door. He got so weak that he didnt want to get up or eat anything. He didn’t even want to drink water. I took him to my vet and they did an xray and found he has an enlarged spleen. He was also dehydrated. We ended up leaving him for 2 days at the hospital so he could get IV fluids and be monitored. Today we had the ultrasound which showed an enlarged spleen and a possible mass. Besides having spondaylosis, he is otherwise healthy. His liver and kidneys look good and so does his blood work. I want to do what is best for him but I am scared of getting the surgery due to his age. Can you please give me some advise? Thanks


  • Karen V on February 23, 2011 at 6:40 am

    Dr. D,
    My lab is 10 years old and I am wondering how you feel about using red clover,
    and Burdock?
    Please advise!
    Thank you,

    • DemianDressler on March 8, 2011 at 10:20 pm

      Dear Karen,
      burdock has some interesting anti cancer effects, although not as well supported as the “big guns” in the Guide (Apocaps, artemisinin and others). Red clover evidence is rather meager in my opinion.
      Dr D

  • carissa on October 10, 2010 at 12:52 pm

    Hi, my dog a male, has a lump on his breastbone area. It has grown signifigantley in the last 5 months. Some people say its a fatty “growth”. I brought my female blue cattle when she was two years, and she had one lower down although her’s has not changed size or shape. His is often red and sore looking, although it does not hurt him if I press on it. Any ideas? Vets are soo expensive in this country, I need to know if I should saving for this. Thankyou.

    • DemianDressler on October 13, 2010 at 4:59 pm

      Dear Carissa,
      as you know, dog cancer is the number one cause of dog death. As you know, how a lump feels and looks does not tell you if it is dangerous. Please get it checked out, at the bare minimum with a fine needle aspirate. Your vet can give you prices. Please don’t wait. See if your vet (or others in your area) take Care Credit, which is a payment plan program that can help with finances.
      Dr D

  • Susan on September 21, 2010 at 9:08 am

    My 12 year old Weimaraner had sudden onset hind weakness in February this year. Our vet felt an enlarged spleen and we whipped it out immediately. It was HUGE!, but my vet felt he got it all. Still, the diagnosis of a hemangiosarcoma freaked me out. We had lost our beloved 9 year old dog last October to cancer. As my 12 year old, Keymos, healed from surgery, we immediatley put him on the full dose of Apocaps (discovered during the previous experience). With a fully nutritious, natural diet, and good supplementation, plus a metronomic chemotherapy from our vet, Keymos has been healthy, happy and strong ever since. The prognosis is dire for hemangiosarcomas, sometimes only weeks. But we are seven months post-op and he is doing great! And we intend to keep doing so. Thank you Dr. D and Apocaps!

    • DemianDressler on September 29, 2010 at 8:47 pm

      Thank you for your kind words Susan.
      Best to you and to Keymos!

  • franklin mattingly on September 21, 2010 at 9:07 am

    just a little over one year ago my white german shepard had a limp that started at 14 year 4 month of age the next thing was she collasped a couple times but came out of it I took her to my conventional vet it was hesocarsonma. she was given 3 weeks to live but I purchased the cancer book dr dressler wrote I also put her on high protien diet steak ect, followed the directions in the book I got here, bought the medical mushrooms and took her for accupuncture treatments she lived a good quality of life for about 23 weeks.thankyou dr dressler.my vet said I could not and would not be able to help her but I was able to help her stay happy and it was worth the time and money I spent.my conventional vet is a very smart man but he did not understand why I was trying to keep her going.he may have resented that I went to a holostic vet but I felt it was my duty to help my old dog.she saved my life one time I would not be writing this now if the dog was not there to protect me that one night.thankyou dr dressler again for your book!I now have a 13 month old WGSD she is a wonerful pet and I am also considering the apocaps.If anyone out there has a dog with cancer it will do you good to read this book.

    • DemianDressler on September 29, 2010 at 8:48 pm

      Thank you Franklin, and I am so pleased to hear that your companion did so well!
      All my best,

  • Ann Marie Reed on September 21, 2010 at 4:18 am

    Dear Dr Dressler,
    Thank you so much for this explanation, and also to the new information on the vaccine. Even though I lost my baby to this awful disease last October I want to know everything I can about it. any one who comes to the canine cancer list I always post and tell them they also need to find the sumner Foundation yahoo group as it is specific for HSA. your book which I loved is always recommended.
    As well I had both my regular vet and my alternate vet apply for your book.It is the same as sittingb across the table and picking a vets brain for five or six hours.God bless you there was and is such a need for your book.
    Ann Marie

    • DemianDressler on September 29, 2010 at 8:49 pm

      Thank you so much for you kind words Ann Marie. All my best,

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