The dog’s spleen is a highly vascular organ that sits behind the stomach. The spleen’s function is a red blood cell processing plant. It filters red blood cells, getting rid of old, damaged, or infected cells. It also stores healthy red blood cells, ready to contract and release these into circulation in the case of emergent need. The spleen is a very helpful organ! Unfortunately, in dogs, the spleen is also a common site for the development of tumors or masses.
Not all tumors or masses are cancerous (malignant); some are benign (noncancerous). The prognosis for a dog with a malignant splenic mass is not good, but surgery to remove a benign mass is curative.
Unfortunately, it’s exceedingly difficult to tell if a splenic mass is benign or malignant until the spleen is removed and submitted for biopsy. If your veterinarian detects a mass in your dog’s spleen, it’s likely that you will have to decide whether to go ahead with surgery to remove the spleen before you know whether the surgery can prolong your dog’s life.
What Are the Expected Outcomes of a Splenic Mass in Dogs?
The most fortuitous scenario involving a splenic mass occurs when the tumor is discovered by palpation on a routine veterinary physical examination. Benign tumors tend to grow to large sizes without otherwise causing problems, increasing the likelihood they’ll be picked up on physical exam. (This should underline the importance of annual or, even better, twice-annual physical exams for middle-aged and senior dogs.)
Discovering a splenic mass in this way, before it ruptures, gives you the opportunity to have an abdominal ultrasound performed. Ultrasound can confirm the mass is in the spleen and can be used to look for any evidence of metastasis (cancer spread) in the abdomen.
Chest x-rays may also be recommended to make sure there is no metastasis to the lungs. If the chest x-ray and abdominal ultrasound show no obvious cancer spread, surgery to remove the spleen should be considered.
Life Expectancy of a Dog With a Splenic Mass
If the splenic mass proves to be benign, the surgery will have extended your dog’s life. While benign masses won’t spread to other organs, they can still rupture and cause your dog to bleed internally, so their removal is necessary for your dog’s survival. A study published in 2018 in the Journal of Veterinary Science found that the two-year survival rate for of dogs who underwent a splenectomy for a benign mass was nearly 78%.
Another study published in 2016 in the Journal of the Veterinary Medical Association found that the median life expectancy of dogs with benign splenic masses was 436 days and that dogs with malignant splenic masses was just 110 days.
If those numbers don’t make it clear, I’ll clarify: Yes, your dog can live without a spleen. She may be more prone to certain infections and less effective at rapidly replacing red blood cells in a crisis, but for the most part, her other organs will step up and take over for the missing spleen.
Spleen Cancer in Dogs: Malignant Splenic Masses
Let’s go back a step. Say your veterinarian has detected a splenic mass in the course of a physical exam, follows up with an ultrasound, and finds that the mass has metastasized.
Malignant splenic masses frequently metastasize to the liver or heart. Either one is bad news, but you may find comfort in the certainty of the knowledge that your dog’s prognosis is poor. Most dogs with malignant splenic masses succumb to their disease within a few months, sometimes even weeks, of surgery. Chemotherapy, used alone or in conjunction with surgery to remove the splenic mass, may slightly improve a dog’s prognosis, depending on the type of malignancy.
There are tools (biopsy, fine-needle aspirate) that, theoretically, could be used in an attempt to determine whether a splenic mass that has not metastasized is malignant, but they are typically inconclusive and the risk of hemorrhage during and after the procedure is high.
The Worst-Case Scenario: Splenic Mass Rupture in Dogs
Unfortunately, many splenic masses are not detected in the course of a routine exam, but are discovered while diagnosing a dog in the midst of an out-of-the-blue medical crisis.
Here is an all-too-common scenario: Your happy and seemingly healthy 10-year-old Golden Retriever is out in the yard chasing balls with the kids, when she suddenly collapses. She looks confused, and though she is alert and responds to you, she is too weak to get up, and she is breathing faster than usual.
You rush her to the emergency veterinary hospital, where the attending vet has a pretty good idea what’s going on as soon as she looks at her gums, which are ghostly white, and feels her abdomen, which has fluid in it. Bloodwork (showing decreased circulating red blood cells) and abdominal x-rays confirm the original clinical suspicion: Your dog has a splenic mass that has ruptured. She is bleeding internally, and without immediate surgery and blood transfusions, she is going to die.
In this scenario, there isn’t time to wait for the results of any tests that may determine whether the mass is malignant (with a poor prognosis) or benign (in which case, surgery may save your dog’s life); you will have to decide on the spot whether to give your veterinarian the go-ahead for emergency surgery to try to stop the bleeding and to remove the dog’s spleen, or to euthanize your dog. It’s a wrenching decision.
Researchers are working on ways to better determine whether a splenic tumor is likely to be malignant or not before surgery. A recent article published in the Journal of the American Veterinary Medical Association by Kristine E Burgess, et al., discussed an online calculator that your veterinarian can use to help predict the outcome for your dog.
“Development and validation of a multivariable model and online decision-making support calculator to aid in preoperative discrimination of benign and malignant splenic masses in dogs,” described a model that uses several parameters including blood test values, ultrasound findings, size of the mass, and how much fluid is present in the abdomen to help predict how likely a tumor is to be malignant, thereby helping owners make the decision whether or not to operate. This online calculator can be found at T-STAT.org.
No Sure Test for Spleen Cancer in Dogs
Knowing if a tumor is malignant or benign before surgery would help a lot, given the grave prognosis associated with malignant tumors of the spleen. Unfortunately, at this time, there is no definitive way to answer that question preoperatively, although we may be getting closer (see “A Potentially Helpful Tool,” above). This leaves you facing a difficult decision for your dog, and makes one wonder – and fear – how many dogs with benign tumors are euthanized, when they might have been cured.
There are some generalizations that may help you make the decision to give your veterinarian the go-ahead for surgery or to euthanize your dog in order to prevent a traumatic death:
- Large, non-ruptured splenic masses found on routine physical exam have the best chance of being benign.
- Small-breed dogs with splenic masses have a better prognosis in general than the larger breeds.
- About two-thirds of all splenic masses in dogs are malignant.
- If you have an older large-breed dog with a splenic mass that has ruptured, the likelihood of this being a benign situation is very low.
- Heritability contributes to the risk of malignant splenic masses; hemangiosarcoma is common in certain breeds, including Golden Retrievers, German Shepherds, and Portuguese Water Dogs. If a dog who is closely related to your dog has had a malignant mass, the chances are higher that your dog will, too.
Oh my heart. My Aussie who is almost 7 was just diagnosed with a splenic tumor. I’m supposed to take him in on March 1 to have an ultrasound and bloodwork, though now after doing some reading, I’m wondering if we should just skip right to surgery. If it is benign but could rupture and kill him, is that a chance I should even take? He seems so young to be having this, compared to the ages of your doggos. But I knew something was wrong, when about a week ago he wouldn’t lay down and was hesitant to walk. I palpated his tummy and he yelped. It has seemed to come and go over the last week, but I decided to have the vet take a look. Sure enough, there’s a mass. This is agonizing and I’m sending my sympathy and love to all of you, because we all understand this pain and anguish as we try to make the best decisions for our furry soulmates.
Please share your experience and outcome as my almost 9 year old Aussie just got diagnosed with a spleen mass and we’re waiting on blood work results now so we’re agonizing over our options now. Obviously I want to what’s best for my girl so putting her through surgery only to loose her a few weeks later is unthinkable. From all the research I’ve been doing, with or without surgery, whether the mass is malignant or benign, she’s a ticking time bomb.
Thank you in advance
I have drawn great sadness but also some comfort reading all your sad and difficult stories about your experiences with your lovely furry companions. I went through exactly this awful unexpected situation with my 11 year old crossbreed Patterdale terrier/Portuguese waterdog, last Sunday: 9th January. Mollie was my loyal, loving, energetic, crazy, companion for nearly 12 years: her birthday was in February. She was a healthy dog but 3 weeks ago she developed a UTI and was checked over by the vet, given a course of antibiotics. The visit did also confirm my suspicion that she had lost weight. I had thought she looked thinner but it’s harder to see in a dog with a rough haired furry coat like hers and earlier this year I had changed to a better quality, less fattening food. Her weight had dropped from 18kg to 15 kg. The vet was not unduly alarmed but this was my 1st return vet visit to that practice in many years, so they had not seen her regularly over the years. My daughter being a vet, and having moved nearer after qualifying, tended to do her yearly check ups. The UTI cleared but returned a few days after stopping the anti biotic. She was given a second course which also seemed to clear it but again she appeared restless, uncomfortable a few days after. She was then booked in for bloods and a scan on Monday. On Saturday she joined me and friends in a lovely long walk, she loved walking with a group. Sunday she was listless, refused her most favourite foods and treats and was not interested in going out. We did a brief walk for ‘business’ but she was glad to get back. Continued to refuse favourite snacks and didn’t even get up to greet some friends who called in. Not like her at all. I rang my vet daughter who suggested I bring her over so she could do some checks. She told me she needed to see a vet ASAP at my local practice: my daughter just having left her practice couldn’t do more complex checks. She was seen by the local vet. Bloods showed discrepancies in red/ white blood cells. She then did a ‘rapid scan’ and discovered a large splenic bleeding tumour. Quite a lot of blood sloshing around her abdomen. I was given two awful choices: an immediate major operation remove the spleen and tumour or to put her to sleep. There was no guarantee that she would survive the operation and checking for cancer could only be done after removal. The most awful decision to make for my darling loyal Mollie dog. My close companion. She had seemed fine on a decent long walk the previous day, she was not suffering majorly other than some signs of possible returning of the UTI. My daughter was with me and explained about the tumour and the risks. She told me to think of Mollie, of her age and her fear of any vet intervention which had always been with her from when she came into my life. The first 6 months of her life she had been passed back and forth between 2 or 3 families. When I found her she was a very insecure young dog who did not appear to have bonded with anyone person. After an agonising 15 or 20 minutes I decided I couldn’t put her through a horrible and risky op with a possible malignant tumour result and further suffering. She was nearly 12 and that age was against her in my decision, as was the weight loss. The cancer of malignancy or not were more than 50/50 in her case. More like 70/30. So I let her go..so awful so heartbreaking. I have been crying every day since but I think it was the right decision for her. The attending vet said afterwards that she thought so too, considering Mollie’s age etc. My daughter was absolutely wonderful, putting no pressure on me in either direction though she said afterwards that she thought I made the kindest choice for my much loved and very loving loyal companion. Gutted..it will take me quite a long time to get over this. I feel so sorry for all of you having similar experiences..but I drew some comfort from knowing that this is not an uncommon experience with dogs, though I had not heard of it. My daughter did know that of course, had dealt with similar cases as a vet, but had never wanted to tell me about such awful situations. Thank you all for sharing your experiences. I think it’s important. Shelley: think of your dogs age..and the risks..
Thank you for this article. We helped our 14 year old morkie cross the rainbow bridge today after being diagnosed just yesterday with a large irregular mass in his spleen. He had a normal day on Sunday and Monday morning awoke with no appetite and severely lethargic. He would drink water when presented with it, but refused to eat even his favorite food. On Tuesday when he showed no signs of improvement, I decide to take him into the vet to investigate what was going on. After doing bloodwork we realized that he was severely anemic and not a viable candidate for surgery especially with the fact that he has a stage 5 heart murmur. We took him home not sure if he would make it through the night, but he did. It was very hard to reconcile in my brain that on Sunday he had a normal day and today, Wednesday, I was having to help ease his suffering. Reading this article and the fellow pet owners’ stories has helped me realize that there was nothing I could have done different. Thank you for sharing your stories and for my fellow grievers, I pray you find peace and remember all the good times you shared with your dog.
May I just say I am deeply sorry for anyone who has experienced this…I am 8 weeks out from losing the love of my life fur baby however I will say, I believe her illness was caused by Bravecto, an oral flea and tick preventative. I have had several dogs over the last 30 years all who have lived well into their senior years, 15, 16….. I attribute their longevity to ignoring prescriptions and being very holistic with their diet and care. Our last dog died within one year of being given two doses of Bravecto, a flea and tick oral preventative medication. I believe in my heart of hearts which is now forever broken that the medication was responsible for her early demise at 9 years young…within weeks of taking her second dose she started having neurologic symptoms, tremors and skin problems and stopped eating. They found a large mass in her abdomen which turned out to be spleen cancer and she died two days post surgery to remove. Massive vet bills aside, I still believe Bravecto was the root cause that took our baby – be aware, it is a pestiside DO NOT GIVE to your fur babies.
I just came home from the vet with my 11-year-old Giant Schnauzer. After a clean bill of health at his check-up in September, he had some vomiting and diarrhea symptoms over the past month and then a small black liquid diarrhea last night that led to X-rays today and the discovery of a large splenic tumor. I am heartbroken and already grieving as I cannot imagine life without him. He is my soul dog.
My question is to those that have gone through this… is the kinder more humane thing to do to put him down before he suffers a rupture? How much pain are they in when that happens? I can’t fathom putting him down, but also absolutely do not want him to suffer and be in pain.
We’re going to get an ultrasound as soon as possible this week with a specialist, but because of his age, the vet didn’t seem to think putting him through the surgery would make sense – regardless of whether it is a cancerous tumor or not. (Average life span is 10-12 years).
Please let me know your thoughts if you have any insights from your experiences. I am so sorry for everyone who has had this experience with their dog💔
Thank you doctor for this article. If you were my vet you would hate me repeatedly asking you what you would do because I know from multiple vet responses that there is no right answer and no crystal ball. Clearly we are all on this article because we all love our furballs and try to educate ourselves as much as possible. hope is normal but not scientific. I have moved on to asking strangers, my horse and goat vet, and beekeeping friends what they would do to no avail. My dog has defied the odds we opted no surgery back in March when he had 4 bleeds and found the tumor. We were thinking quality of life versus surgery (his dislike of vet stays from his bout with leptospirosis a few years back and recovery challenges of keeping a lab/border collie cross mellow on a hobby farm) so since March he seemed recovered albeit ultrasound showed huge tumor on spleen and they don’t just go away I know. Now he’s bleeding again since last night and I’m second guessing myself all over again! Heartbreaking and frustrating. I thought he was going to die (again) abdomen distended, white gums,he was cold couldn’t get up, and very thirsty. but after 12 hours He’s coming around again vet said must have clotted he’s on pain meds for arthritis. Back in April they didn’t want to operate on his hematoma on his ear then he was so stable in December vet suggested operation (he was surprised he was still alive my daughter works there) and here I sit thinking I missed the window or was this time a gift maybe it wasn’t malignant because he lasted so long and now I’ve let the time bomb get bigger when I could have done something? Just venting great article and that website tool looks useful I’ll share with vets if they don’t already know. one of our vets just lost her dog a week after surgery to this so I know they love and care as much as we do. Vets are my favorite people even when it’s tough stuff like this.
I’m sitting here with my 11 yr old lab mix and his third or fourth rupture. He recovered from all the previous ruptures ands it’s been 10 months since the first one. This article and comments are spot on. Being 10+ and a larger dog we were leaning towards probably cancer and an operation at this age would be too traumatic. Our vet is amazed he has made it 10 months and through at least 3 or 4 bleed outs that we know of. I guess it can stop bleeding but no telling if it will or will not. Maybe because he has made it 10 months it’s not cancer. Maybe he will survive tonight and this rupture. Maybe we operate if he does and maybe he survives the operation. I went through this with my dad for a year and right now this feels just as bad. I’m doubting myself, I should have operated earlier (maybe), I should euthanize now as he is suffering (maybe) or maybe he will recover again. I’m crying, no maybe.
My dog recently had a large tumor removed. The vet told us years ago the lump was just fat and not to bother with surgery. It got bigger then ruptured and started bleeding. We had no choice to do surgery. The biopsy came back and it was grade 3 soft tissue sarcoma. He was recovering well and then wasn’t acting like himself. He stopped eating so we took him to the vet and he had a fever. Thru prescribed antibiotics and the fever broke, all to just come back weeks later. They would give him fluids to bandage the problem but we wanted an answer as to why he kept having fevers and wasn’t as spunky as his normal self. His bloodwork and urine came back fine. Eventually they did an xray and saw a mass but couldn’t determine if it was on his spleen or liver. Vet said best case would be spleen bc it can be taken out, if its liver u can’t do anything. We then did an ultrasound and were told its a large splenic mass with some fluids on the abdomen. I asked what we can do next and was told they believe its malignant but won’t know for sure unless we remove the spleen and biopsy it. I’ve been crying since as my baby has been through so much the last few months and has been a fighter. Do we put him through another surgery and pray its benign or is this risky and may come back malignant and spread within 2 months. I’m so stuck. We don’t want to give up but don’t want to put him through any trauma or pain..help
My poor Bentley was doing fine, even had his senior check up about a month ago along with labs, everything was great. This past Wednesday I came home on my lunch real quick and walked it and he couldn’t move, was so confused, and weak, I took him to the ER Vet and he had a mass on his spleen that had ruptured. I was devastated I could barely even talk to the vet to ask all the right questions. I knew the facts and that most are malignant and that the surgery was kinda risky…because of COVID I wasn’t allowed in at first…but I asked the vet if I could see Bentley before making my decision, and after walking in and seeing how miserable he was I couldn’t put him through that surgery with the potential of more issues further on…I decided I wanted him to have a peaceful death with no suffering. It was the hardest decision I ever had to make especially knowing he was completely normal that morning. This was all so sudden but I know my baby didn’t suffer and when I walked in he just looked like he was ready to go 🥺
I cried when I was reading your story. I don’t know how I will face that decision. After the surgery to remove the spleen my baby boy is doing better every day. But I know that this will not last long. The vet says in about 2 month there will be a metastatic event with another internal bleeding but at that time there will be no organs to remove to help him. It will be slow death or he will go to sleep.
Going through this now with my boy and its so hard to decide when he is still happy and wagging his tail to think of putting him to sleep is heartbreaking 💔
My beloved baby 9 yr old Ibizan hound just had his spleen removed after it got raptured. My vet suspects it’s malignant. Now 3 days after his surgery he is back home and would not stop whining. It breaks my heart. Sometimes he randomly screams in pain. I hope that is not due remote metastatic tumours. I hope to try him on iamyunity. I have also asked my vet to reach out to university of Minnesota to see if the can try him on their experimental drug called EBAT. Long shot but I have nothing else to try.