Spleen Cancer in Dogs: Signs, Treatments, Prognosis

Spleen Cancer in Dogs: Signs, Treatments, Prognosis

Spleen Cancer in Dogs: Signs, Treatments, Prognosis

Spleen cancer is one of the most common forms of cancer in older dogs. What makes this disease extremely deadly is the rapid progress and ability to strike without warnings. 

For dog owners, it’s essential to learn more about this devastating disease, its causes, and the best forms of treatment. In this article, we will answer all the queries you may have about Hemangiosarcoma in dogs.

Key Takeaways

  • Spleen cancer can be a silent killer for older dogs.
  • Symptoms are hard to notice, but weakness, loss of movement, and swelling of the abdomen are some indications.
  • Surgery and chemotherapy are the common forms of treatment.
  • Recovery time is usually around two weeks for most dogs.
  • The survival period can be between 4 to 6 months after treatment.

Dog Spleen Tumor Symptoms

In most cases, there are no specific clinical symptoms of splenic hemangiosarcoma. Owners often report the occurrence of sudden internal bleeding, which may be caused by the rupture of the spleen or surrounding blood vessels. Splenic masses can get spotted on a routine abdominal ultrasound or radiograph.

These tumors are life-threatening as they have a higher risk of metastasis or spread and spontaneous rupture [1]. Recognizing the symptoms is vital to check the growth of the disease before it turns into an emergency.

A few other clinical signs to look out for include the following:

spleen cancer in dogs

  • Weight loss and weakness
  • Lameness
  • Intermittent collapse or seizures
  • Muscle incoordination 
  • Partial loss of movement 
  • Dementia
  • Pale mucous membranes
  • Rapid heartbeat 
  • Abdominal fluid accumulation or swelling of the abdomen
  • Intermittent lethargy or fatigue

What Breeds of Dogs Get Spleen Cancer?

Research has pointed out that a few breeds are more prone to splenic mass formations that lead to cancer in dogs. German Shepherds, Golden Retrievers, and Labrador Retrievers are breeds that are commonly affected. Among small breed dogs, Beagles and Terriers are most at risk [2].

Other breeds that are affected include: 

  • Bernese Mountain Dogs 
  • Portuguese Water Dogs  
  • Boxers 
  • Flat-Coated Retrievers 
  • Skye Terriers 

The disease is often more lethal for older dogs (above seven years of age) diagnosed with hemangiosarcoma.

What Causes Spleen Cancer in Dogs?

Splenic hemangiosarcoma in dogs is an intriguing disease since its exact causes are still unknown. It’s cancer in the cells that line the blood vessels. While it mainly occurs in the spleen, other sites like the heart and skin are also prone to this form of cancer. The reason behind the localization is not known.

It has been estimated that 5-7% of all tumors seen in dogs are related to hemangiosarcoma. Since some breeds are more affected than others, experts suspect that heritable factors are a major reason. 

It is also assumed that genetic risk factors combined with long-term environmental causes lead to mutations. Environmental factors also include exposure to toxic chemicals or carcinogens.

These causes may lead to a series of mutations that give rise to a splenic mass and lead to ruptured blood vessels. A simple mutation does not always lead to cancer, as the body has an in-built mechanism to eliminate such cells. 

However, more mutations enhance the overall risk factor. With more research, we will be able to eliminate these factors at an early stage.

Canine Spleen Cancer Diagnosis

Once the clinical signs of the disease are diagnosed, a vet can conduct a series of tests to confirm the development and spread of cancer. In 25-50% of dogs with a splenic tumor, the growth has ultimately proved to be benign [3].

Abdominal Ultrasound and Other Imaging Tests

Abdominal X-rays can be conducted to detect a splenic mass or the presence of free blood within the abdominal walls. Fluid samples are also collected to confirm the signs of internal bleeding.

In order to evaluate the subtle cellular changes or abnormalities in the spleen, ultrasonography is used. They can show masses within the spleen or liver, which can be benign. However, X-rays, ultrasonography, or CT scans are not very effective in determining the type of tumor. 

In such cases, MRI tests can be more effective in distinguishing between malignant and benign splenic tumors [1].

Blood Tests

The spread of cancer in the body can not be detected by imaging tests alone. A set of blood tests are often recommended, including a CBC (for checking the red and white blood cells and platelets), clotting times, coagulation studies, and a chemistry panel for checking kidney and liver functioning. 

Splenic masses tend to bleed intermittently before a large rupture. These small bleeds can affect the results of the blood work and lead to detection.

Blood tests are also conducted to check the functioning of other organs, including the heart, which can help determine if your pet is ready for surgery. Furthermore, biopsies can be used to confirm the evidence obtained from the imaging tests.


A urinalysis is also often done to detect the type of tumor. The presence of blood or abnormal cells in the urine can confirm the presence of a malignant tumor.

Dog Spleen Cancer Treatment

Unfortunately, the treatment options for hemangiosarcoma in dogs are limited. More so due to the late diagnosis of the disease in most cases. Generally, veterinary surgeons remove the tumor from the spleen, which is usually followed by chemotherapy.

spleen cancer in dogs


The primary treatment for splenic masses is the removal of the affected part via surgery. It is best to perform the surgery before the tumor or tumors rupture. In case a rupture has occurred, emergency surgery is the only option. 

If there is sufficient evidence of the metastatic spread of the tumor in other organs, surgery is not recommended. 

The spleen acts as the blood filter in the body and removes the worn-out components from the blood. It can also provide an emergency supply of blood to the body.  In general, the liver can manage the functions of the spleen if it’s removed. Still, the risk of infection remains after splenectomy.

Note, the surgery can result in a Hypovolemic shock due to blood loss, and a blood transfusion may be necessary. After surgery, a biopsy is conducted on the spleen to determine the need for further treatment through chemotherapy. 

Dog Spleen Removal Cost

The cost of surgical removal of the spleen can be between $2,000 to $3000. If a blood transfusion is needed after surgery, it can further cost $500 to $700. If the pet is older and has other health complications, the surgery alone can be more expensive.


It has been reported that the use of chemotherapy after surgery has provided the longest survival periods for dogs with splenic masses. 

A common agent used for the treatment is Doxorubicin. It is generally used for 4 to 5 sessions with 2-week intervals. Studies have shown that the survival times can vary between 107 to 257 days, depending on the stage of the disease [3].

The side effects of chemotherapy can include nausea, vomiting, diarrhea, and reduction in appetite. It can also result in lethargy and thinning of the coat. 

However, most owners have reported that these conditions can be handled effectively without too many issues. Since chemotherapy may have toxic effects on the heart, an echocardiogram may be conducted before the treatment.

Metronomic Chemotherapy

In traditional chemotherapy, the chemical agents are administered at maximum tolerated levels. However, some veterinarians also recommend metronomic chemotherapy, where lower doses of chemical agents are administered more frequently [4]. The treatment is based on the health condition of the pet and the stage of the disease.

This approach can be as effective as the conventional method, with the added advantage of being less toxic for the animal. In fact, some studies in veterinary medicine have indicated that this treatment can effectively eliminate the endothelial cells in blood vessels and retard tumor growth rate and metastasis.

Radiation Therapy

When surgical procedures are not advisable, a few large doses of radiation therapy is often used to reduce the size of the splenic masses. Radiation therapy has also proved to reduce the amount of bleeding from the tumor. This can be followed by chemotherapy.

Overall, the role of radiation therapy is mostly used for local control of tumors. It also helps to relieve pain and improve the overall health condition of the animal. However, in the case of metastatic growth, clinical use of radiation therapy is not advisable.

Clinical Trials for Dogs With Spleen Cancer

There are clinical trials that are conducted to evaluate the effect of specific agents on canine splenic hemangiosarcoma. Usually, the trials are conducted with oral medications that have antitumor and antimetastatic properties.

Yunnan Baiyao Supplements

Yunnan Baiyao (YB) is an ancient Chinese herbal supplement that is being used in veterinary practices. With tests conducted on laboratory rats, YB has been effective in decreasing bleeding times [5]. A few studies conducted on human subjects have also indicated positive effects of YB on internal bleeding and ulcerative–hemorrhagic conditions [6].

There are no detailed studies on how it affects the blood coagulation system in dogs or the exact volume of the dosage. Some studies have indicated that the medicine is safe for canine patients. While there is significant potential for YB with metronomic chemotherapy, more clinical trial data is required to establish definite outcomes.

Canine Spleen Cancer Prognosis: What To Expect

Canine patients can live a normal life after splenectomy. A successful splenectomy alone may give your dog an additional median survival period of three months. If the tumor is found to be malignant after the surgery, chemotherapy is commonly used to increase the patient’s lifespan. 

If chemotherapy can be successfully employed after surgery, the surviving period may be lengthened by a few more months.

spleen cancer in dogs Typical survival time for malignant or benign splenic tumors
The typical survival time for dogs with splenic tumors is about 15 weeks
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265589/

Dog Spleen Removal Aftercare

In most cases, the dog can return home within a week after the splenectomy. The period of full recovery depends on the animal but is usually around two weeks. Since the spleen can be a heavy organ in large dogs like German Shepherds and Golden Retrievers, the animal can appear thinner after the surgery.

Here are a few points that you need to take note of after your dog is back home:

  • Progress: Your pet may feel groggy or show signs of pain or discomfort for the next few days. The attitude and appetite should improve steadily within two to three days. If there is a lack of progress, consult the veterinarian for assistance. Also, your pet should urinate within 24 hours of returning home from the surgery. 
  • Prevention: Since the operation requires a long incision on the abdomen, a bandage will be applied to prevent bleeding. The movements of the dog and all rigorous activity will have to be restricted during the recovery period. The use of a short leash and other forms of protection like an e-collar is recommended. 
  • Attention: In case of any discharge or swelling in the skin around the incision, consult your veterinarian. The redness or swelling around the site should come down with time. 
  • Future Progress: The results of the biopsy are commonly available within a week after the surgery. The veterinarian can advise you about the next course of action. In addition, the animal should also be diagnosed by the veterinary team after two weeks of the surgery to check the rate of recovery.

Dog Spleen Tumor Life Expectancy Without Surgery

The survival time in canine patients diagnosed with hemangiosarcoma is low. This is due to the aggressive nature of the malignant cells which spread fast. 

Without surgery, survival time for dogs with splenic masses can range between a few days to a few weeks. An untreated splenic mass can rupture suddenly, leading to heavy internal bleeding. This can be fatal if emergency treatment is not provided.

Pain Relief for Dogs With Splenic Mass

Generally, veterinarians provide antibiotics and pain relief medications after surgically removing the spleen. The overall pain management program is determined by the progress of the disease and the owner’s plan towards tackling the condition. 

Since the owner is most familiar with their pet’s normal responses and physical movements, they need to notice any minor changes. 

NSAIDs are the medicine of choice for pain relief in most cases. For more severe pain, opioids used for treating bone cancer in dogs are used. These include codeine, hydrocodone, fentanyl, and torbutrol.

During chemotherapy, you can consult the veterinarian regarding the changes required in the pet’s diet, along with the requirements for appetite stimulants and other drugs to reduce side effects.

The use of hemp products like cannabidiol (CBD), is also suggested for cancer therapies, including pain relief [7]. CBD can decrease pain and inflammation without leading to conditions like cognitive impairment. 

However, further clinical studies are necessary to understand its exact role when used in combination with traditional methods of treating splenic masses.

When to Euthanize Dog With Spleen Tumor?

In some severe cases, splenic hemangiosarcoma may not respond to treatments. It may also reach an advanced stage even before diagnosis takes place. Depending on the stage and the overall prognosis, the veterinary surgeon can suggest putting the animal down.

The owner needs to choose by balancing between the signs of the dog’s pain and quality of life. While this is an emotionally painful choice, it might be the most peaceful way for your pet to pass away in that condition.


Here is a quick look at some of the common questions related to canine spleen cancer.

How Long Do Dogs Live With Spleen Cancer?

The median survival time for canines with a malignant splenic mass with combined surgery and chemotherapy is 4-6 months.

How Long Will a Dog Live With Hemangiosarcoma?

Without undergoing surgery or therapy, the survival time can be around a few weeks. In reality, the exact survival time is unpredictable in such cases.

How Long Will a Dog Live After Spleen Removed?

In a recent study, the average survival time with surgery alone was estimated at 1.6 months [8].

Is Splenic Tumors in Dogs Painful?

The spleen tumors are not painful in their initial stages and canine patients may not show any clinical signs of being affected. There can be some pain and side effects when the blood vessels rupture or the disease spreads to other organs in the later stages.

What Percentage of Spleen Tumors in Dogs Are Benign?

In general, 25 to 50 percent of the splenic masses are benign. 


Dealing with a pet suffering from malignant tumors can be a heartbreaking experience. As the owner, you need to be aware of the subtle signs of cancer in dogs, to establish a quick time of diagnosis. It is also important to understand the available veterinary options and choose the best one for your pet.

While we are a long way from getting a medical cure for this devastating disease, the life of your pet can be extended with a quick diagnosis and the right remedy.


  1. Lee, Mokhyeon, et al. “Presurgical Assessment of Splenic Tumors in Dogs: a Retrospective Study of 57 Cases (2012-2017).” Journal of Veterinary Science, The Korean Society of Veterinary Science, 30 Nov. 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC6265589/. 
  2. KC;, Fernandez S;Lang JM;Maritato. “Evaluation of Nodular Splenic Lesions in 370 Small-Breed Dogs (.” Journal of the American Animal Hospital Association, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/31099604/. 
  3. “Advances in Hemangiosarcoma Treatment – WSAVA2008 – VIN.” Powered By VIN, www.vin.com/apputil/content/defaultadv1.aspx?pId=11268&id=3866584. 
  4. B;, Biller. “Metronomic Chemotherapy in Veterinary Patients with Cancer: Rethinking the Targets and Strategies of Chemotherapy.” The Veterinary Clinics of North America. Small Animal Practice, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/25174901/#:~:text=Metronomic%20chemotherapy%20is%20characterized%20by,a%20lower%20risk%20of%20toxicity   
  5. Frederick, Jami, et al. “The Effects of Oral Administration of Yunnan Baiyao on Blood Coagulation in Beagle Dogs as Measured by Kaolin-Activated Thromboelastography and Buccal Mucosal Bleeding Times.” Canadian Journal of Veterinary Research = Revue Canadienne De Recherche Veterinaire, Canadian Veterinary Medical Association, Jan. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5220596/. 
  6. Yang, Bo, et al. “The Efficacy of Yunnan Baiyao on Haemostasis and Antiulcer: a Systematic Review and Meta-Analysis of Randomized Controlled Trials.” International Journal of Clinical and Experimental Medicine, e-Century Publishing Corporation, 15 Mar. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC3992384/.
  7. Henry JG;Shoemaker G;Prieto JM;Hannon MB;Wakshlag JJ; “The Effect of Cannabidiol on Canine Neoplastic Cell Proliferation and Mitogen-Activated Protein Kinase Activation during Autophagy and Apoptosis.” Veterinary and Comparative Oncology, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/33247539/. 
  8. “Survival Time of Dogs with Splenic Hemangiosarcoma Treated by Splenectomy with or without Adjuvant Chemotherapy: 208 Cases (2001–2012).” Survival Time of Dogs with Splenic Hemangiosarcoma Treated by Splenectomy with or without Adjuvant Chemotherapy: 208 Cases (2001–2012) | Journal of the American Veterinary Medical Association | Vol 247 , No 4, avmajournals.avma.org/doi/abs/10.2460/javma.247.4.393.