Splenic tumors in dogs are one of the trickier issues to catch early. Cookie’s story illustrates how a complicated health saga saved her life.
This was the second time that horrible things seemed to have to happen to save our dog’s life. If the story played out any other way, would we have discovered Cookie’s splenic tumor on time?
Why splenic tumors in dogs can go undetected
Some health problems manifest loudly—limping, lumps and bumps on the skin, diarrhea, vomiting, licking and scratching, hair loss. Outward signs make it readily apparent there is a problem. The spleen, however, is tucked deep in the abdomen. You cannot see that it looks wrong—a tumor can grow undetected and undisturbed.
By the time a mass is large enough to be felt on physical exam, it can already be quite advanced. Preventive abdominal ultrasounds can detect splenic tumors early. But that isn’t foolproof either, unless you luck into the perfect timing. How often would you need to get them? Annually? Twice a year? Even more frequently?
Yet, wellness exams remain essential. Don’t skimp on wellness exams.
Cookie’s broken toenail
The whole story started with a broken toenail. One night, Cookie began paying undue attention to one of her hind feet, licking it excessively. I knew better than to dismiss it. But I couldn’t see anything wrong. Armed with a strong flashlight, glasses, and a camera, all I could detect was what seemed to have been just a crack on one of the nails. I sent photos to Cookie’s vet, and they couldn’t see a reason for all that attention either.
As it turned out later, the main problem was under the nail, where I couldn’t see it.
Because Cookie was clearly bothered by it, I made an appointment with her veterinarian in hopes they could figure it out better up close and personal.
The toenail came off
The morning of the appointment, I found a strange thing on the floor—closer examination revealed it was Cookie’s toenail, which had now fallen off. Both Cookie and the nail went off to the clinic.
I admit that, as much as I was trying not to, I became extremely concerned about cancer. I hate the paranoid part of me, so I was eager to accept the veterinarian’s diagnosis, toe nail infection. We did discuss the tumor angle, but she was quite sure. As well as a therapeutic trial with antibiotics was the least invasive starting point.
Cookie didn’t like the toe as much, but it was extremely sensitive to touch. When she bumped it on anything, it was obvious it hurt like hell.
Organizing a biopsy
With toe cancer still in the back of my head, I kept thinking about getting a biopsy. The problem with that was Cookie’s low tolerance to any sedation drugs. Yet, the nagging feeling in my gut led me to request that the biopsy be done.
Before I got an appointment time, I received a written estimate. That is commendable—every hospital should do that for any larger or more costly procedure. Yes, in all the years, this was the first time I received one. Why?
The cost was high, but Cookie was insured. So not a big deal. What freaked me out, though, was the amount of drugs listed. I have received enough bills for surgeries to know what one looks like. And this estimate looked just like that.
Did they grab a cost estimate template for surgery and not adjust it? Or did they mess up and quote for a surgery—amputation? The whole point of taking a biopsy was to determine whether amputation would be needed.
Further, the appointment was months away.
Stepping back
The whole thing felt to me like a sign to step back. Cookie’s leading veterinarian re-examined the toe and remained convinced it was a stubborn infection and not a tumor. Under these circumstances, long-term antibiotic treatment seemed the best option.
Diarrhea was a concern, and I took all measures to try to prevent it. But it came. It came with a vengeance.
We hoped that it would resolve once Cookie was on the meds. Well, it did not.
Diarrhea continues
Everybody was convinced that the long-term antibiotics were the cause of Cookie’s diarrhea. And time went on. I tried multiple probiotics to restore her microbiome. None of them helped.
Changes in appetite
As time went on, along with the diarrhea, Cookie started losing her appetite, too. And when she did want to eat, she would eagerly take some food, and then it seemed that, even though she would have wanted more, she couldn’t.
That was the last straw. Were we missing the forest because of the trees? How long could we run with the antibiotics fallout hypothesis? My gut told me there was something else going on. The symptoms felt to me like a potential obstruction.
Imaging
I was determined there was more going on than met the eye. We took Cookie back to the clinic. We were not going to leave without some imaging being done—I thought we were looking for an obstruction or such thing. No, I didn’t think Cookie ate something wrong. But that’s what things looked like to me.
The clinic staff wasn’t impressed—they’ve had a long, busy day. But seeing that we weren’t indeed leaving, they decided to do a quick ultrasound got get rid of us.
A mass on the spleen
And there it was—evidence of a splenic tumor, and a quite large one at that. My heart sank—it was quite a shock. I needed a few minutes to put myself together.
What I knew about dog splenic tumors
Most of the time, dog splenic tumors don’t get discovered until the dog is bleeding out internally. That is a dire situation. We could consider ourselves lucky finding out before it came to that. In fact, Cookie wasn’t exhibiting any of the warning signs. Her only issue was diarrhea and appetite changes.
Up to two-thirds of dogs with splenic masses have malignant tumors. Two-thirds of the malignant splenic tumors are hemangiosarcomas. Not so great, but a chance that Cookie’s could have been benign.
Treating splenic tumors in dogs
The veterinarian started telling me there were things they could do to keep Cookie comfortable. But that was not my thinking. The best course of action with splenic tumors in dogs is one thing—take it out.
First of all, the only way to identify the type of splenic tumor is to take out the spleen and analyze the tissues. Don’t get fooled—a dog can bleed out from a benign tumor just as well.
Secondly, if the tumor is benign, the dog might gain two years of quality of life. If it is cancerous, it will make their last weeks comfortable, even if you opt out of the chemotherapy option.
One way or another, the solution was clear—get the spleen out ASAP. The veterinarian seemed surprised, but this was the easiest medical decision I have ever made for my dog. We booked the splenectomy for the first available surgical appointment. They wanted to refer us to a specialist, but how long would that take? And it was winter, what if we couldn’t make it there? Fortunately, one of the experienced local surgeons agreed to do it.
Dog splenic tumor removal complications
Are there potential complications with splenectomy? Well, of course. Every surgery has potential complications. Beyond the obvious potential complications during removing a dog’s spleen include:
- bleeding
- infection or sepsis
- cardiac arrhytmias
- injury to neighboring organs such as stomach or pancreas
How many of these did Cookie suffer? Heart arrhythmia and pancreatitis. The surgery went well, but the morning after, Cookie was in dire condition. It was touch-and-go for a few days. Yes, I still knew I made the right decision.
While we were dealing with all that, we were waiting to learn what her splenic tumor was. At the time of surgery, it was huge and already seeping. It could have started fully bleeding at any moment.
Cookie’s splenic tumor pathology results
Through the turmoil of Cookie dealing with the surgical complications, the verdict finally arrived. She had a myelolipoma. However weird-sounding the word that is, it is a benign splenic tumor, and splenectomy is curative. That was excellent news and a reason to keep fighting through Cookie’s complications.
Cookie has recovered and gained a year and a half of quality of life. She passed two days short of her 12th birthday, to an unrelated issue.
What about the diarrhea?
Of course, Cookie’s diarrhea had improved only temporarily, only to return. Not even the prescription diet she had to be on because of the surgery-induced pancreatitis made a dent in it. Eventually, we resolved it with a soil-based probiotic and digestive enzymes.
And what about the toe?
The original plan was to take a biopsy during Cookie’s splenectomy. But when the surgeon examined it, she felt strongly that it was cancer. She suggested amputation during the procedure, and I agreed. I was cancer after all—that’s the last time I beat myself over being too paranoid. Fortunately, the margins were clean, and that took care of that.
Of course, there were complications with that, too, but that’s a whole other story.
Final notes on dog splenic tumors
As much as I always lean toward a conservative approach, splenic tumors are the one thing where an aggressive solution is the best, most of the time. Be aware of this potential problem and know the early warning signs. They can be quite subtle. Always be proactive when something about your dog is off. Early signs of a splenic tumor can be very vague:
- subtle behavioral changes
- lethargy
- wax-and-wane arthritis acting up
- decreased appetite
Once your dog develops full-blown symptoms, it’s already in big trouble.
Emergency signs of a ruptured splenic tumor
The spleen is essentially a sponge filled with blood. Splenic tumors—even the benign ones—contain abnormal blood vessels and fragile tissue. Once a tumor ruptures, blood spills rapidly into the abdomen, and the situation can become critical within minutes. Dogs can go from “a bit off” to a full-blown crisis frighteningly fast.
- rapid, shallow breathing
- enlarged abdomen
- extreme weakness or inability to walk
- pale gums
- sudden weakness or collapse
When you see these things, drop everything and rush to your veterinary hospital or ER.
Latest information on dog splenic tumors by Dr. Sue Ettinger, the cancer vet.
Directed toward veterinarians, but essential information for dog parents to advocate for their dogs better.
Related articles:
Types of Canine Splenic Tumors: Are Splenic Tumors Always Malignant?
Early Signs of Splenic Tumors: What You Probably Didn’t Know about Splenic Tumors in Dogs
Canine Splenic Tumors: Walks Like A Splenic Tumor, Quacks Like A Splenic Tumor … It Must Be A UTI?
Splenic Tumors in Dogs: Buddy’s Distended Abdomen
Splenic tumors are notorious for growing silently and rapidly. Studies suggest some hemangiosarcomas can double in size within 1–4 weeks, depending on how aggressive the cancer is. Benign masses tend to grow more slowly but can still become large before showing any symptoms. Because growth happens deep inside the abdomen, you often won’t notice anything until the tumor is quite advanced or ruptures.
Sometimes — but only if the mass is already large.
Most splenic tumors stay hidden behind the ribcage until they reach a size where they push the abdomen outward or displace other organs. By the time a vet can palpate a mass, it’s usually already big and has been growing for some time. That’s why a normal abdominal palpation does not rule out a splenic tumor.
Ultrasound is the best screening tool we have — but timing is everything.
If the tumor is small or has just begun forming, it may not be visible, especially if the mass hasn’t distorted the spleen yet.
Even with perfect technique:
A tiny or early-stage tumor may be missed
A benign mass can look similar to a malignant one
A clear scan only reflects the moment in time
To reliably catch hemangiosarcoma early, you’d theoretically need ultrasounds every 1–3 months, which isn’t realistic for most owners.
There’s no universal answer, but many internal medicine vets recommend:
Annually for senior dogs with no risk factors
Every 6 months for breeds at higher risk (GSDs, Goldens, Labs, flat-coats)
Immediately if there are vague symptoms like lethargy, poor appetite, or “not quite right”
Even then, early splenic tumors can slip through the cracks.
It depends entirely on whether the tumor is benign or malignant:
Benign splenic masses (hematoma, nodular hyperplasia):
Surgery alone often cures the condition.
Malignant hemangiosarcoma:
Surgery alone: 1–3 months
Surgery + chemo: 4–7 months
Rare exceptional cases: 9–12 months
Owners often don’t know which type it is until after the spleen is removed and biopsied.
Yes — if they receive immediate emergency care.
Dogs can compensate briefly, but once a splenic tumor ruptures, internal bleeding can progress to shock within minutes to hours. Emergency surgery can save dogs with benign tumors, but the prognosis for malignant ones remains guarded.
Unfortunately, splenic tumors typically produce no early signs at all.
But subtle clues can include:
intermittent lethargy
decreased stamina
off-and-on appetite
quieter behavior
vague discomfort
These are easy to mistake for aging, which is why many splenic tumors go undetected.