As veterinarians, we’re often the bearers of difficult news. 

This Memorial Day, I experienced the heartbreak that comes with losing four dogs to a silent killer: splenic tumors. 

Just a day later, my mentee faced the same tragedy. 

These cases are devastating for families and veterinary teams alike, and they highlight just how stealthy and dangerous splenic tumors can be.

The spleen is a highly vascular organ nestled in the abdomen, quietly performing crucial functions like filtering blood, storing red blood cells, and supporting the immune system. 

Unfortunately, it’s also a common site for tumors in dogs, especially as they age. 

These growths can be benign (non-cancerous) or malignant (cancerous), but both can be life-threatening if they rupture.

Among splenic tumors, about two-thirds are malignant, and of those, two-thirds are hemangiosarcoma — a particularly aggressive and insidious cancer. 

Hemangiosarcoma arises from blood vessel cells, making it prone to rupture and internal bleeding. The suddenness with which these tumors can steal a beloved pet is nothing short of shocking.

One of the most tragic aspects of splenic tumors is their stealth. 

Dogs often show no outward signs until the tumor ruptures, causing sudden internal bleeding. 

The classic presentation is a dog who seemed perfectly fine one moment, and then collapses or shows signs of weakness, pale gums, rapid breathing, or a distended abdomen. 

By the time these symptoms appear, the situation is often critical.

This unpredictability is what makes splenic tumors so heartbreaking. 

Owners may not have any warning. The dog might have enjoyed a walk that morning or begged for treats just hours before. Then, suddenly, everything changes.

In the past, our diagnostic options were limited. I remember the pain of losing my own dog, Ranger, to a ruptured splenic tumor at just seven years old. At the time, we didn’t have access to advanced scans or specialized blood tests. The diagnosis came too late.

Today, veterinary medicine has advanced. We can now offer a combination of diagnostic tools to catch these tumors earlier—sometimes before disaster strikes.

Routine blood work can sometimes reveal clues—anemia (low red blood cells), changes in white blood cell counts, or evidence of internal bleeding. 

However, these findings are not specific to splenic tumors and can be seen with many other conditions.

One of the most promising advances is the development of new in-house cancer screening tests. These tests can detect certain markers in the blood that suggest the presence of cancer. 

While not definitive, they provide valuable hints and can help guide the decision to pursue further diagnostics.

Abdominal ultrasound is a powerful, non-invasive tool for visualizing the spleen and detecting masses or nodules. 

With skilled hands, we can often distinguish between benign and malignant growths, assess for internal bleeding, and look for evidence of spread to other organs. 

Ultrasound can also be used to guide needle biopsies, providing tissue samples for diagnosis.

When a splenic mass is discovered, the best course of action is usually surgical removal of the spleen — a procedure called a splenectomy. Surgery can be life-saving, especially if performed before the tumor ruptures. Dogs can live healthy lives without their spleen, and benign tumors removed surgically can mean a complete cure.

Unfortunately, if the tumor is malignant — especially if it’s hemangiosarcoma—the prognosis is guarded. Even with surgery, this cancer often spreads to other organs, particularly the liver and heart. The longer the tumor has been present, the worse the outlook.

Chemotherapy is an option for dogs diagnosed with malignant splenic tumors, particularly hemangiosarcoma. 

It’s important to note that chemotherapy in pets is not the same as in people. 

Our primary goal is always to preserve quality of life, not just prolong it. 

Most dogs tolerate chemotherapy remarkably well, with far fewer side effects than people experience. 

Many continue to enjoy their favorite activities and routines while undergoing treatment.

Chemotherapy can extend survival time and, in some cases, provide months of good quality life. 

It’s not a cure, but it can give families precious extra time with their beloved pets.

Every decision we make in veterinary medicine is guided by one core principle: the quality of life for our patients. 

We work closely with families to weigh the options, considering not just the medical facts, but also the pet’s age, other health conditions, and the family’s wishes.

Sometimes, the most compassionate choice is to say goodbye. 

Other times, surgery and treatment can give a dog months or even years of happy life. 

There’s no one-size-fits-all answer, and every case is unique.

While we can’t prevent all cancers, there are steps owners can take to improve the odds:

• Regular checkups: Annual or biannual veterinary visits are crucial, especially for older dogs. Early detection is key.

• Know the signs: Sudden weakness, pale gums, collapse, or a swollen abdomen are emergencies — seek veterinary care immediately.

• Ask About screening: If your dog is a breed prone to splenic tumors (such as German Shepherds, Golden Retrievers, and Labradors) or is a senior, talk to your veterinarian about the possibility of screening tests or ultrasounds.

Losing Ranger to a splenic tumor was one of the hardest moments of my career and life. 

At the time, we didn’t know what we know now. 

Today, we have better tools, more knowledge, and more hope than ever before. 

My team and I are committed to using every resource available to catch these tumors early and give our patients the best possible chance.

If you have questions about splenic tumors, cancer screening, or your pet’s health, please don’t hesitate to reach out. 

At Guardian Animal Medical Center, we’re here to listen, educate, and advocate for your pets—every step of the way.

MJ Wixsom, DVM MS is a best-selling Amazon author who practices at Guardian Animal Medical Center in Flatwoods, Ky. GuardianAnimal.com 606-928-6566