Is It Cancer? Never Assume

Many pets get the wrong treatment because a mass is assumed to be cancerous.

Benign sweat gland cyst in the tail of a 9-year-old Labrador.

Photos Courtesy of Dr. Phil Zeltman

Suggested Veterinary Products

Many patients never get the surgery they need or are euthanized because veterinarians or owners assume that a mass is cancerous.

It’s not uncommon for a referring veterinarian to call me to perform surgery on a patient with a “splenic tumor.”  I tend to call it a “splenic mass” until proven otherwise by my pathologist. Understandably, clients often don't want to put their pet through surgery if it's likely to be cancer. But that’s obviously a decision based on their family vet’s assumption.

The truth is, it sometimes doesn't really matter if a mass is benign or cancerous. A benign mass can cause some very annoying signs depending on where it is located: a large mass in the rectum preventing a dog from defecating; a large cervical mass pushing on the trachea and causing severe dyspnea; a large axillary mass preventing a dog from using the leg normally.

Benign intestinal mass in a 9-year-old Golden (jejunal leiomyoma).

These masses might have been benign, but they still caused some significant signs that dramatically affected the pet's quality of life.

We recently did surgery on three patients; all the names used here have been changed. "Everybody" just knew they had cancer. But their owners just loved their pet too much and couldn't put them to sleep without at least the benefit of surgery.

Max is a 13-year-old male Sheltie. X-rays revealed a large splenic mass. Based on the way it looked on ultrasound, we believed the mass to be malignant. Taking an ultrasound-guided biopsy of the spleen is possible, but it can be risky; the mass can rupture and the biopsy can cause "seeding."

Despite the odds, John, Max's owner, was interested in surgery, which was performed the next day. The mass was the size of a cantaloupe (in a Sheltie!), and looked really ugly–i.e. vet code for "Man, this oughta be cancer." Max recovered uneventfully.

One week later, the biopsy came back as … benign! The mass was a myelolipoma. Max is now expected to have a normal quality of life and a normal life expectancy.

You May Also Like  Penn Vet doctors receive NIH grant to target canine autoimmune disease

Jake is a 12-year-old male cocker who had difficulty urinating. Ultrasound showed a large mass in his bladder. Bladder masses are much more often cancerous than benign. Linda, the owner, elected to have the mass excised anyway.

We took Jake to surgery a few days later and removed about one third of his bladder.  One week later, the biopsy came back as … benign! The mass was a leiomyoma. Jake should have a normal life expectancy and a normal quality of life.

Praline, a 9-year-old Labrador, had a pretty big mass under the tail. She was referred for a tail amputation, because the mass was thought to be cancer. For some reason, call it a gut feeling, I wasn't too thrilled to do that, and of course neither was the owner.  So we decided to remove the mass only. 

Upon section postoperatively, the mass appeared dark, so I was concerned it could be a malignant melanoma. One week later, results came back: the mass was benign!  It was a cyst in a sweat gland.  Again, this mass will not affect the patient's life span, and Praline got to keep her tail.

The list could go on.

The moral of the story: Never assume.

I am perfectly aware that the diagnosis could just as easily be bad. In fact, it was supposed to be, based on experience and statistics. But here are three older dogs, some would say in the last part of their lives.

They all were statistically "supposed" to have cancer. But these loving owners, willing to provide the best possible care for their pet, were not going to give up without a fight. In fact, out of countless patients who did have cancer, I don't remember a pet owner ever regretting choosing surgery over euthanasia, no matter how much extra time we bought.

The goals of tumor removal are to obtain a diagnosis, improve the patient's quality of life (e. g. being able to urinate or defecate or breathe), increase life span, and decrease future risks (e.g. by preventing a hemoabdomen secondary to rupture of a splenic mass).

You May Also Like  The trends to watch for in the veterinary world

Over the years, I have become much more cautious when a pet owner asks me whether I think a tumor is benign or malignant. I simply say, "I don't have microscopic vision," and that I just don't know.

Some clients hate this answer, but I would rather say that than give a client unnecessarily poor odds or false hopes.

In the case of Max*, Jake* and Praline*, three extremely dedicated owners were rewarded with an excellent diagnosis, an outstanding prognosis, and hopefully many more happy years with their dogs.

Dr. Zeltzman is a mobile, board-certified surgeon in Allentown, Pa. He is the co-author of “Walk a Hound, Lose a Pound.”


34 thoughts on “Is It Cancer? Never Assume

  1. I very much enjoyed these happy ending stories. Our twelve yr young labrador, Roxanne-Love, had two masses on her spleen. We opted for surgery…results came in benign! Our prayers were answered. This all took place in the last month. I was asking the vet at the hospital, where our Roxy had her surgery, what happens when pet owners come in with sick pets and they want to save them, but can’t afford surgery?? Roxy’s surgery cost us $4300. For some that is a drop in the bucket and for others it might as well be $100k. I can only imagine how helpless pet owners must feel if they can’t afford to try and save their pet’s life. 🙁

    I can’t imagine life without puppy dogs!

    1. My dog roxy was diagnosed with a mass on her spleen today! She goes in for surgery tomorrow! I can’t believe our dogs have the same name and both have a splenic mass…can I ask what your roxy’s symptoms were? Was the mass affecting her heart at all? Or causing her to be anemic?

  2. Thank you for this article. Most have told nightmare stories and scared me to death!! My 11 year old springer mix had a cantaloupe-sized mass on her spleen and it was removed yesterday. Now we wait for the results…Wishing for the best, and so thankful there are surgeons who can help. To all who have a dog with a mass…keep up the hope and spirit and give plenty of love!

    1. We are bringing our 8 year old lab in tomorrow morning for spleen removal and this is the first article I’ve read that has had anything leaning towards good news so we are praying for the best. Good luck with your fur baby

  3. My cat is 6 years old and just had a mass removed from her spleen two weeks ago. The results came back and they could not say for sure 100% what it was. I know I don’t want to put her through chemo. She has been back in the hospital for 8 days now due to anemia and the cause is not 100% determined either, even after lots of tests. So far she has had 3 transfusions…1 before the surgery and 2 after. Now that she is on steroids her HCT levels are staying up. It’s all a mystery.

  4. Our labrador Chloe was diagnosed a couple of weeks ago with a HUGE splenic tumor, the size of a watermelon. It was crowding out all of her other organs and the vets only used the word tumor to describe it. Euthanasia was the recommended course of action as Chloe is 16.5. I sought a second and third opinion and all vets said euthanasia should be performed that day. They actually told me that to put her through surgery would be cruel as her prognosis was so poor, the cancer had probably spread and we would only gain a few weeks with her, but at what cost to her with the anesthesia and surgery recovery. We opted to operate anyways as I just couldn’t part with her and I knew she wasn’t ready to say goodbye. Chloe had surgery the next day and all went well, her recovery was swift, and the results of the histopathology came a week later – it was BENIGN!!!!
    We are well aware that she will not live very long anyways as she is already quite old but we are so happy that we followed our hearts and saved her life!!! Just like this article says, don’t ever assume the worst and always keep hope and faith in your animal. Think what they would do for you in the same situation and do that for them. Always give them a chance and do not give up, even against ALL ODDS. You never know!!!

    1. A fantastic note. Many thanks for writing it.
      Our beloved 13 year old black labrador Zorro is on the operating table as I write, having a large mass on his spleen removed. Fingers crossed the growth is benign. Your note has encouraged me to push hard for a biopsy when the vet calls (if they suggest otherwise).

    2. Thank you for this post. My 15 year old poodle just got his spleen removed today. Hoping it’s benign and so glad your dog’s tumor was benign!

  5. I know this article is old but the comments are newer and all of it gave me hope.

    My cat just had surgery to remove what turned out to be two large masses in her abdominal area. The vet said her organs look great and her lungs were clear and he thinks it is related to some leftover ovarian tissue that the vet who spayed her left in. She has exhibited signs of heat twice a year since I got here so it makes sense. We’re waiting to get the results of the histopathology to see if it’s benign or malignant.

    I’m so glad I found this article because it gave me encouragement to get this thing taken out of her and not just let it go.

  6. My 13 1/2 year old cocker just had a spleenectomy….removal of spleen and a baseball sized ugly tumor…
    One vet said to euthanize, the other…knew my heart had to know for we opted for
    Like everyone else….all I have read are death sentence stories…and I hold my breath as
    I wait for Buddy’s histopath report!
    He has no other lesions, no bleeding into the abdomen….blood tests are all normal!
    I am praying my gut is right….BENIGN….but if not….I will do everything in my power to make him comfortable…

    thanks all!

  7. Hi …my Chandler …shihtzu…has a spleen mass also. His symptoms were not eating…or eating very little for a doggie who always loved his food for 12 years. We had unltrasound on Friday that showed he has a mass on his spleen. It is the holidays now. So I am waiting on our vet to return and hope to get a call tomorrow to set up probable surgery to remove this mass whether benign or not. The ultrasound said there were 2 masses one was 2 inches the other was smaller. He is mildly anemic. I have been living on pins and needles waiting for xmas and New Years to pass so that we can move forward to make him feel better. He is drinking and eating small portions of (I made him filet minon steak). He really has no interest in the food though unless you hand feed him. Prayers this is benign and removal makes him feel better and eat.

  8. My 13 year old German Shepherd Diesel is booked in tomorrow for splenic mass removal. Fingers and paws crossed it’s benign. He is my best friend….

  9. Our 7 year old toy fox terrier just has her spleen removed. A 5cm tumor in it. We are awaiting biopsy results. Oct 2016, we lost another TFT, 6 year old, hemangioscarcoma in the jaw.
    Just praying we don’t lose our other little girl…

  10. Yesterday at emergency vet our 7 year old Brittany Spaniel was found to have a large, unruptured, splenic mass. We elected to hold off on surgery until we could talk to our family vet today. His recommendation was to not do surgery. I’m torn! I want to give him that chance, but I don’t want to put him through surgery if the outcome is grim 🙁 My mom doesn’t want to do the surgery, I do, but I don’t want to push her into doing something she is not comfortable with…

  11. Our German Shepherd has had trouble going to the toilet and tries several times a day our vet showed us an xray and thinks there is a mass preventing him from going to the toilet he has on occasions passed normal stools he shows none of the symptoms of cancer he has not lost his appetite and runs like a pup he is 5 years old, he is seeing a specialist on monday

  12. My friends’ beautiful dog was diagnosed with a spleen tumour last September, following a major bleed, which he survived. His owners opted not to have surgery. Now it is nearly March and he is still alive and acting like a puppy still, there are days when he is a little slower but overall he is amazing…he has had two minor bleeds, where he is clearly not feeling great, one can see the colour of his gums is pale, but he comes back. I took care of him for four weeks and eliminated the dry food, preparing every day meat with some veggies and quinoa. During that time he had no bleeds. His owners have now changed his diet so he is eating more meat, I do not know about the dry food. As my dear friend had Ovarian cancer and had trouble with digesting food, I reasoned that this dog’s digestive system might be compromised and hence I gave him easily digestible food. The mass is very large, he was a very slender dog and now looks like he is a little overweight, probably the mass is the size of a cantaloupe. He is 10 or 11 years old, a mixed breed of setter and pointer (I think). I wonder how long he can continue, he is much loved, he has outlived the original thoughts by 3 to 4 months. Has anyone had a similar experience? Does anyone think the food might be helping?

    1. Tell your friends to research Yunnan Baiyao. It is a Traditional Chinese Medicine supplement that helps with bleeds. There are several great groups on Facebook – one is the Ketogenic Dog Group (special high fat diet for dogs with cancer) and Hemangiosarcoma Diet & Supplement Protocols for dogs – A holistic Approach.

  13. My dog was diagnosed with a splenic mass today. She is 15 and has a torn acl but gets around well and is generally in very good spirits. I am debating the best course of action and hoping someone whose elderly dog went through surgery can tell how their dog faired in the months following surgery. Thanks!

  14. My 13 year old beagle Kali, the love of my life (I’ve had her since she was 8 weeks old), had a splenectomy today to remove a very large ruptured mass. Without emergency surgery she would definitely have died because of the internal bleeding. It was torturous to be faced with the possibility of my child being fine a day ago and dead today. There was no way that I could just put her to sleep without having the surgery and subsequent biopsy. She did well in surgery and there are no signs of any other masses. It will be about a week before the biopsy results are back. I am hoping beyond hope that the biopsy is benign. I love her so much and I just know that our beloved animals want to fight and need us to fight for them! The bond we develop with our pets really helps in times like I had with Kali today – Everything in my gut said she wanted to risk having the surgery. My gut and my heart also said that I couldn’t bear the thought of losing her today, especially without giving her a chance to recover.

    I’ve been reading about these masses for a few hours and almost all of the information I’ve found left me feeling hopeless about it being benign but then I found this site and it helped me SO much to hear that it could be benign. Thank you all so much for sharing your stories and for everyone on here that’s lost their pet, my heart goes out to you! 🧡


  15. Our 9 year old Golden Doodle Lucee now has the same issue. We are deciding on whether to do the surgery or not. But thanks to this article I believe we have no option but to opt for the surgery. She has a grapefruit sized tumor hopefully on her spleen. Fingers crossed, we can’t wait to talk to the Vet on Monday morning. Thank you for all the positive comments!

  16. My 12 year old Golden has 3 small masses on his spleen initially detected by x-ray and confirmed by ultrasound. A biopsy was performed and it was negative for cancer. Our vet recommended surgery. We consulted with a Board Certified Surgeon today and he recommended against surgery at this time. We have used this surgeon before and he is excellent. He recommended another ultrasound in 3-4 months to monitor the size of the masses. This surgeon (and another surgeon in the room at the time) stated that small non-malignant masses pose very little risk of a bleed. The reason to monitor is that it is always possible that the biopsy was wrong or the masses could get larger. He stated that malignant masses tend to grow faster. In any event, that is good news for now.

  17. I just found out that my dog has a large mass in her cervix,i dont know what to do..any suggestions, please help

  18. To all dogs and owners that have been down this unfortunate road of pain and discomfort. I ask god to please give strength and hope to you all. Just last night I found a golf ball mass just above my dog Kodas back right leg. He seems too be 100% healthy still eating and drinking and running around. He is Only 4yrs old and I’m just wondering if it’s common for dogs at his age to get cancerous mass at that age? Any advice would be greatly appreciated. God Bless

  19. My 9.5 year old lab had his enlarged spleen removed 4 days ago. Symptoms were that he was lethargic, panting and refused to eat. After his operation the vet said his intestines were also twisted. I’m waiting for the results and my stomach has been in knots. Fingers crossed for benign. He’s eating well now and looks to be feeling great, well besides the fact that his stomach is all stitched up. He’s my best friend and I just love him!!!

    1. Well received a call from my vet today and results are in….benign!!! I had tears of joy and couldn’t stop hugging my boy for hours. I’m so glad I chose to operate and save his life. I had to give him that chance…that chance should be the one thing you do for your pet. Good luck and have faith.

  20. My 9yr old lab has a large mass we cant tell if its attached to anything. Breaks My heart to not go down fighting. Best bird dog Ive ever had/ seen. Im leaning towards surgery. Really bugs me is these outrageous prices most vets quote. Thank god i found a reasonable one.

  21. My almost 14-year old dog began collapsed on Friday (8/10) and urinated on the floor. She looked as if she were unable to move. However, on Saturday I took her and the other dog for an hour and half walk, and she did fine. Then on Sunday afternoon she collapsed again, and seemed to be paralyzed for a few seconds. Monday night when I was walking her again, she had another episode of collapse, but was able to resume movement after a short time. Nevertheless, I carried her part of the way back home. I stayed up until 2 a.m. watching her. Tuesday morning (8/14) she was up about 5:30 a.m., just lying on the bed in an upright position. She did get up and drank a lot of water. She came back to the bedroom, but she went again to the kitchen to drink some more water. A little later she was walking again towards the kitchen, and she threw up the water and stomach contents (about three times). She fell against the wall, but she recovered. I took her to the vet. She was a little lethargic, but she became very animated when she saw the vet’s office and started barking. She wanted to explore the grounds before I took her into the building. After x-rays and a blood test, the vet told me she was somewhat anemic and the collapses were probably the result of a lack of oxygen in her blood. The x-rays showed she had a tumor either in the spleen or liver. He couldn’t tell. He said if they did surgery and the tumor was in the spleen, they could remove it, but if it were in the liver, there was nothing more to be done. Surgery seemed so “iffy” to me, so I opted for euthanasia. However, I am having so much regret. I was there for the euthanasia procedure. Before that, my dog just wanted to go home; she kept going to the door. I wonder whether I should have just taken her home and given her a few more weeks of life. I have put down two dogs previously, but they were both in the throes of death. This dog was still eating and interacting with life. However, I was concerned about the collapsing problem, and the vet said the tumor could rupture. My dog had surgery a month or so ago after having been bitten by the other dog, and she recovered nicely from that. At that time her blood work was normal. I didn’t want my dog to suffer, but I question whether I could have given a few more weeks of a quality life. The only other symptom I noticed prior to the collapse episodes was an intermittent lameness about a couple of times when we walked, but it seemed to resolve itself because she walked that hour-and-a-half walk very well.
    I really don’t know if I made the right decision. I wouldn’t have wanted her to suffer, but I was unsure about the continued effects that this tumor was having on her system.

  22. I noticed maybe four months ago my coonhound looked a little fuller in the ribs and abdomen. Two weeks ago I noticed the fullness was a hard mass between her sternum and navel. She had no other symptoms. A trip to the vet, and x-ray and some blood work showed a large mass on her spleen. Blood work indicated that the mass had not ruptured but had microscopic bleeds. The vet recommended the veterinary surgical center the next town over. They quoted me over $5000, which was completely undoable. My vet then agreed to do the surgery for $1100. It was more risky because splenic tumors tend to bleed excessively and he could not do a blood transfusion. It was worth the chance and my vet removed a mass the size of a football. It was touch and go for the first 24 hours after surgery but a week later, she’s as good as new. The pathology exam discovered that the tumor was a myelolipoma, a benign tumor made up of blood vessel an d fatty tissue. It will never come back

  23. My 12 year old chihuahua had some blood in her urine. ultra sound revealed a small mass in her bladder but they couldn’t tell for sure if it was cancer. i opted for a urine test that detects cancer she is only 4 pounds 7 ounces so anything invasive was out. the test came back today negative 85 per cent no cancer cells. we are opting for another urine test that will tell 95 percent. she will pass this test too and then some steroids to shrink the small mass in her bladder. we are so happy. there is hope for every dog with a mass and i will pray for all of them to be benign

Leave a Comment


Your email address will not be published. Required fields are marked *