Dog Cancer – Symptoms and Diagnosis

two female dog friendsThis is the second article in a series this month on canine cancer. In the Facts About Canine Cancer I highlighted the fact that cancer can occur in any part of your dog’s body, and multiple tumors can grow at each cancer site.

Because of this, it’s not easy to give definitive symptoms of cancer; however, the AVMA (American Veterinary Medical Association) has identified 10 common signs of cancer.

It’s a good idea to become familiar with the symptoms listed below and start taking notice of how your dog presently looks, feels and behaves so that you’ll be able to spot any changes. This doesn’t have to be an onerous task, just become more alert to any changes as you bath, groom, exercise and watch your dog.

10 Common Signs of Cancer in Small Animals:

1. Abnormal swellings that persist or continue to grow
2. Sores that do not heal
3. Weight loss
4. Loss of appetite
5. Bleeding or discharge from any body opening
6. Offensive odor
7. Difficulty eating or swallowing
8. Hesitation to exercise or loss of stamina
9. Persistent lameness or stiffness
10. Difficulty breathing, urinating, or defecating

If your dog is showing any of the above symptoms, make an appointment to take him to the vet as soon as you can. One of the factors determining the successful treatment of any cancer is early diagnosis and treatment.

Some tumors are very aggressive, and early detection and treatment is vital if your dog is to have the chance of fully recovery.

How is cancer diagnosed?

The procedure for detecting, and identifying the type of tumor present can be time consuming as your dog may need to undergo one or more of the following procedures:

  • Initial physical examination by your vet – your vet will discuss with you the symptoms you’ve identified and will perform a physical examination of your dog. Sometimes your vet will see a tumor on your dog’s skin or in his mouth, or feel a tumor in your dog’s body – if this is the case further tests will need to be performed to identify the nature of the tumor.
    If your vet finds nothing to make him believe your dog has any symptoms of cancer, and does not recommend any further tests you can always request that additional tests be undertaken to rule out the presence of a tumor and/or ask for a second opinion.
  • Blood and urine tests – in some tumors, cancer cells are present in your dog’s blood so completing these tests may reveal the presence of cancerous cells, and the type of cancer can sometimes be diagnosed.
  • X-rays of tumors can help to reveal the extent and location of a tumor in your dog’s body.
  • An ultrasound examination enables your vet to look at your dog’s internal organs to identify the presence of any tumors.
  • CT or CAT (Computed Axial Tomographic) or MRI (magnetic Resonance Imaging) scans – these tend to give much more detailed results than either x-rays or ultrasound examinations. They can make the diagnosis that much more accurate, and may remove the need for further invasive tests to determine the nature of any tumor that’s present.
    CT and MRI scans are usually only available at specialty veterinary hospitals or referral centers, and are expensive procedures. Both procedures will require your dog to be anesthetized since any movement they make whilst the scan is taking place will result in the images being unreadable.
  • Cytology – this is the examination of cells taken (aspirated) from your dog’s body, basically a vaccination in reverse. Cytology can be an accurate diagnosis method, but it does have its limitations – not all tumors will give up their cells when a sample is taken, sometimes only blood is taken. Whilst cytology can diagnose malignant tumors, it can’t eliminate the presence of cancer when only blood has been taken in the sample.
  • Surgical biopsy – this is the most certain way to diagnose cancer in your dog. The procedure involves the removal of tissue which is then examined under a microscope.
    Your dog may have an incisional biopsy, where only a small part of the tumor is removed, or an excisional biopsy, where the whole tumor and surrounding normal tissue is removed. Which type of biopsy you dog will have will depend upon how big the tumor is and where it is located.

So, there are number of procedures that your dog may have to endure to ensure a correct diagnosis, and it may take several days to get the results from some of the procedures.

In the next article I’ll look at some of the more common types of canine cancer.

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  1. Great series! Thanks for the info. Woofs, Johann

  2. Thanks Johann – it’s not an easy subject to read, or write, about, but I think it’s an important topic to cover.

  3. My doggie is haven’t a cancer, any website or information can help to face it?



  5. nicole-ann says:

    oo thank you!!!this article may help save my dogs LIFE!!!!i just recently descoverd some random sweelings on her and i m gonna go get them checked out!!!

  6. My She[herd has most of these symptoms and he is only 4 years old. Its real sad.

  7. Hi, I have a 3 1/2 year old pitbull cross and he has 4 of the symptoms listed. He has recently lost 10lbs, has lumps on him in various places, is getting quite lame, is cold alot, sleeps alot, and just is not himself. I am taking him to the vet tomorrow. I suspect cancer, but I hope not! Thanks for your info!

  8. Our 10 year old German Shep is in the last stages of bone cancer in rear leg, it is so difiicult to know when to let her go. She is still eating, up to a week ago was still going out for a walk (is now only going in garden), now having difficulty in going to toilet, but passing urine okay. I’m now sleeping downstairs with her. Can’t imagine what xmas day will be like if she goes in the next few days. Shes been a wonderful dog and we’ve been really lucky to have her.

  9. My Malamute who is 14 has a very large mass on her side that was removed once without anesthesia and within 2 months has returned with a vengance. The Vet says we can’t do Surgery due to her kidney function. Up until yesterday she has appeared happy and has been eating. Then I took her for her usual small walk and half way through it she sat down and would barely move. I barely could get her home and now she will hardly get up at all and seems to be in pain. I wonder if this is the cancer that has caused this latest development or maybe a small stroke? This is breaking my heart. I spent all night petting her. I can’t move her to get her to the vet so I guess I will get some help.

  10. HI, further to my previous post our german shepherd Sasha was peacefully put to sleep at just after mid day on 23rd December. We were completely shattered, so much so that I had a heart attack at 4.30am the next morning and have been in hospital. Our doctor has been fantastic – he says that a patient loosing their dog is no different to another patient lossing a human member of their family and that the grieving process will take at least a year and it is totally normal to miss our pets to such a degree.
    We were very priveledged to own Sasha and we miss her beyond words.

  11. I just recently learned that my beautiful sheltie has lymphoma. I took him for just a regular check up and shots, thinking he had a cold or kennel cough. He had been coughing a short time and became very tired,, although I thought it was just his underactive thyroid which we have been treating him for 2 yrs. I am very sad and shocked to find after the vet extracted some fluid and sent out to the lab it indeed is cancer. Please have your dogs check if you notice any different behavior–he was also having trouble with bowel movements. Due to his thick fur coat it was really hard to tell he had lost 10 pounds in a yrs. time. Teddy is on prednisone and we will have to put him down when he seems to be suffering. We love our 6 yr old dog and will miss him greatly!!

  12. Terrill Moran says:

    My daughter and her husband lost their eight year old little Penny, a chihuahua, last July. Still today they both are still taking Penny’s death so hard. The husband, Mike, has withdrawn from Church and a big part of his life. Nothing in life seems to mean a lot to him anymore. He blames God for taking his little girl from him. The type of cancer Penny suffered from was Hermangia sarcoma, the deadliest of all canine cancers, whic has no treatment. Mike’s main problem was and is that small breed dogs like Penny rarely get this form of cancer, so in his heart, he needs answers as to WHY?.Why Penny of all the animals in the world was she chosen to bear such a painful and deadly cancer. If anyone has any words that may bring some understanding and peace to Mike, please respond to this letter. Thanks and God Bless.

  13. I have a 9 and half year old rat terrier that we cannot locate the source of his cancer. He has developed fluid in both his chest and abdobmen. I have spent $1500 over the last week seeing specialist in the area and even took him to a University Vet Hospital. No diagnosis given other than the cancer is “possibly” somewhere in his body. I cannot take appropriate actions to fight the cancer! SO Frustrating.

    I am thankful for each day I have with him. Pain meds are taking the edge off, but the fluid build up is so upsetting to him and me.

    What is the most shocking to me is the young age of most dogs on this forum with cancer. So purebreds, others not. I know how hard it is to let go, but I am trying to prepare myself for the enivitable. Hardest thing I have ever had to come to grips with as it is awful not knowing what is wrong with my little guy. All I can do is pray and place faith in God.

    May all of the posters find peace in knowing that your pet will be with you again in Heaven.

  14. alison looker says:

    I have a ten year old lab x, he has just been to the vet for a stomach upset, the vet found a suspected mass, that she thinks is very invasive, and could only give him a few more weeks, i love my dog dearly have cried non stop, he is my all, he has always been there and always makes me smile, i have the choice of non invasive option with a poor prognosis, or if lucky surgical treatment that at the age of ten could kill him, i just want to spend as much time with him as i can and when he seems like hes had enough then i will have to let him go, i know im being selfish but im not ready to let him go yet, probably never will be, especially as he is so active and apart from the poop problem is his usual happy self, he is part of my family and i really dont think i will ever come to terms with the loss of such a wonderfully loving companion.

  15. Im so sorry about Penny. My black Lab Jackie is eight years old and was just diagsosed with Osteosarcoma. Bone Cancer. Unfortunately there is nothing we can do but wait. Chemo is too expensive and we dont want to put her through that. She loves running and eating and playing ball. She is still doing all of this. I dont believe that the world wants to take Jackie away. It doesnt seem real. I hate this

  16. My sad story is similar to Penny. On Dec 15th my 11 pound 7 year old Yorkie named Sugar had her “well pup exam” and she was fine. On dec 31st at 2 am she went into acute respiratory failure and died. I insisted on an autopsy. Suggee Bear had a primary cardiac carcinoma (aggressive hemangiosarcoma) with metastasis to the lungs. She had NO symptoms. I love my little Suggee Bear and miss her so much. I am thankful that 1 year ago we adopted a poodle “Bella.” Instead of pulling away from church Mike should go to a grief class. Pray for strength. Also, there are so many rescue chihuahuas that need a good home. I am already going on Yorkie rescue sites and, in time. will adopt another Yorkie. Good luck and God Bless!

  17. Hello I have a pittbull his name is Goldie we had him for about 8yrs now. I’ve notice growth by his gentiles, I’ve given him medication, but itgets smaller then reappears later, it seems to be hard and filled with some blood.I starting to think it could cancer, I’m praying its not , any advice I would truly appreciate it Thanks Diana

  18. It’s hard to write this but my darlng dog Ziggy who is like my child has pretty much all of the symptoms listed above. Three days ago she was very slow walking at the park then she was staggering and was vomiting and breathing rapidly and harder than normal. I carried her back to the car and took her straight home. She was wobbly on her feet all weekend, breathing hard and had diarrhoea but no more vomiting. Her tummy was big and hard like a beach ball and she would barely eat anything even yummy treats like a little bit of vanilla ice cream that would normally have been gobbled down were left uneaten. On Sunday she did manage to eat a small amount of bbq chicken and roast beef. Took her to the vet Monday morning and he felt her abdomen and said there are lots of lumps inside her abdomen and it is probably cancer. She is 13 going on to 14 but I only got her 5 months ago after her owners gave her away because they were having a baby. The frst month she was so depressed but now I feel like we are really bonded. I love her so much and while I knew taking her in to my home and in to my life that she could get sick and pass away due to her age, (She is an English Staffy and they live on average 12 yrs) I still feel so incredibly upset and sick with grief. I am trying not to be so upset because I still have to wait for a definite diagnosis but I just have a feeling like I know that it will be cancer. 🙁

  19. Mike so sorry to hear about your beloved Penny. I have lost 5 dogs over the years to cancer so I understand your pain. But good did come from it. I feel like my babies caused me to search for answers and now I am helping pet owners learn the things that are causing are dogs to die from cancer. The #1 killer to dogs is accendents and #2 is cancer [so in my mind cancer is #1] to many vaccines, ingredients in food, once a month flea and heartworm treatments, toxic shampoo, lawn treatments the list goes on and on. Our dogs don’t have a chance with all of this. The media and vets tell us these things protect our pets when the truth is its killing them. During this painful time educate yourself to these issue and help Pennys life save others, nothing speaks with more power than a person searching for anwsers and spreading the word. Some of my favorite and powerful sites . Dr Karen Becker, DVM; Dr. Jane Dobbs, DVM:,, Susan Trixtion: [I am not at my office so I hope I have listed these correct] Please fell free to e-mail me with any question
    Michele McKinney

  20. My 12 year old Border Collie, princess has just been diagnosed with terminal cancer. Ten months ago I took her to the vet for a lump on her chest the vet said it was a fatty tumor. I took her back in because the lump grew they did surgery two days ago and took lump and some mammary glands. They told me she is terminal. One of the hardest things is not knowing how long she has left. Princess is a joy to all who meet her. I have noticed that some of my cats now do not want to be around her. I will cherish every day I have left with her.

  21. we had a 2 year old labradoodle we adopted 6 months ago.. she was diagnosed with bone cancer.. we amputated. eveything went well.. the x rays after were all clear.. she did 2 chemos, eveything went great. she was aboutto do the third one. when she started not breathing right and not feeling well..

    took her to teh vet, x rays showed it had spread to her lungs.. there was nothing more we could do… we had to put her down. we all said our goodbyes first.. and we were there for it.

    she died with us both there in my arms.. it hurts.. because I dont know how she got it. she was so loving . i cannot believe such a sweet loving animal ws taken from us

  22. I have a 11 yo lab Lacey, she had a cancerous growth just under the skin removed two months ago. She now cannot walk or stand up on her hind legs. The cancer is coming back. I have been praying to God to take her in her sleep as I just cannot put her down. My heart is crushed as she has gotten me through the death of my only son, I’ll never get over it, but she gets me through each day with God’s help. I beleive He uses her to help me. For Michael, remember God loves animals and He has a special place for them. The Bible says there are animals in Heaven. Please, return to church and ask God to forgive you for blaming Him. He has a job for her in Heaven and you will see her again. Just as I say this, I have to prepare myself for that day too. God Bless all the wonderful pets we have been so fortunate to have abd embrace.


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