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Treatments for Dogs with Hemangiosarcoma

Updated: Mar 31

This article focuses on the experimental treatment options for dogs with hemangiosarcoma.

Conventional Therapies:

Conventional cancer therapies, including surgery, chemotherapy, and radiation therapy, have been widely used for decades but have limitations, and sadly this is especially true for hemangiosarcoma.

A two-year old pup, Hanako, was found with advanced hemangiosarcoma on Christmas Day 2016. No treatment options were offered by the vet to her devastated parents.

One way to visualize the efficacy of treatments is by looking at the Kaplan-Meier survival curves that plot the percentage of patients alive over time.

In this example from a retrospective study that looked at 154 dogs with splenic hemangiosarcoma (see Figure A) the overall prognosis is quite poor with surgery.

When these patient dogs are put into groups based on the clinical stage of the disease (see Figure B), you can see that prognosis is better for dogs in stage 1, but the median survival time is still in the order of months, not years.


Can adding chemotherapy help?

One study compared the survival times of hemangiosarcoma patients who had surgery with those who had surgery and chemotherapy. Adding chemotherapy seems to only add extra few months.


With the help of research and new clinical trials, more hopeful prognosis and survival trends may be possible in the near future.

Experimental therapies for hemangiosarcoma

The following list consists of new therapies being evaluated in clinical trials as well as old therapies (approved for other indications) now applied to hemangiosarcoma, hence available without being qualified for a clinical trial.

Please ask your veterinarian if any of these treatments might be suitable for your pup.

Propranolol with doxorubicin

Locations: Anywhere, Chemo + propranolol protocol may be used by any vet who thinks it might help the animal without being part of the official clinical study.

Clinical trial locations: St. Paul, Minnesota (U of Minnesota), Philadelphia, Pennsylvania (University of Pennsylvania), West Lafayette, Indiana (Purdue University)

What is it? Early studies have shown that a drug commonly used to treat heart disease, propranolol, can kill hemangiosarcoma cells in the laboratory. The drug has also been effective in reducing disease progression and increasing the survival time in people with angiosarcoma, a cancer very similar to canine hemangiosarcoma as well as effectively treating babies with benign hemangioma. This study will test three dose levels of propranolol along with standard doxorubicin chemotherapy for safety and benefit to dogs with hemangiosarcoma.

(Please note that an increasing number of veterinary oncologists in the US are incorporating chemo+propranolol protocol into the treatment plan)

Data: Retrospective study data has been shared by a veterinary team from South America at the World Veterinary Cancer Congress 2024. Watch our Apr 2 2024 Webinar for more information. Publications for angiosarcoma and angioma for human patients can be found via Google Scholar.

Contact: Amber Winter,

Yale Canine Cancer EGFR/HER2 Vaccine

Locations: Edmonds, WA (Bridge Animal Referral Center), Pullman, Washington (Washington State University Veterinary Teaching Hospital), Salt Lake City, Utah (MedVet Salt Lake City), Cleveland, Ohio (MedVet Cleveland), McMcMurray Pennsylvania (MedVet Pittsburgh), Fairfax, Ohio (MedVet Cincinnati), Phoenix, AZ (IVO Integrative Veterinary Oncology), Santa Cruz, California (Pacific & Santa Cruz Veterinary Specialists), Chicago, Illinois (MedVet Chicago), Manassas, Virginia (MedVet Northern Virginia)

What is it? Members of the ErbB family of tumor proteins are overexpressed on a number of

canine cancers and often is indicative of a poor clinical outcome. Herein, we describe a novel immunization approach to induce a polyclonal anti-EGFR/HER2 immune response in canine patients with tumors associated with ErbB tumor protein expression. Canine patients were immunized and boosted with a short peptide of the ErbB extracellular domain with shared sequence homology between EGFR, HER2, and HER3. Recent small study has shown that EGFR peptide vaccine may be effective at controlling the progression of hemangiosarcoma in some dogs. (Funded by CAA)

Data: Pilot data mostly for osteosarcoma can be found here and here Hemangiosarcoma data from a small study was presented at the VCS meetings.

Contact: Mark Mamula,

Rapamycin Study

Primary Location: San Diego, California

Veterinary Specialty Hospital - Sorrento Valley

Secondary Locations: Williston, Vermont (Peak Veterinary Referral Center), Waukesha, Wisconsin (Wisconsin Veterinary Referral Center), San Marcos, California (Veterinary Specialty Hospital - North County)

What is it? Rapamycin is an immunosuppressive that has significant anticancer activity. It has been approved for use in several human cancer indications. Anecdotal reports of Rapamycin activity in canine hemangiosarcoma and other cancer types have been made over several years, however, its activity has been unpredictable. Recent genomic analysis of these cancers provides a scientific basis for this sporadic activity based on the existence of several genotypes that may each be uniquely responsive to Rapamycin. Based on its reported tolerability in dogs (alone and in combination with chemotherapy) it is reasonable to now ask if Rapamycin may improve treatment outcomes for dogs with cancer. This study will be evaluating the tolerability of a novel formulation of Rapamycin. The latest version of this study seeks to do so with a novel, oil-based formulation of the drug.

Data: None yet

Contact: Samuel Stewart,

Personalized Therapies for Dogs with Hemangiosarcoma

Primary Location: Woburn, Massachusetts

Massachusetts Veterinary Referral Hospital

Secondary Locations: Williston, Vermont (Peak Veterinary Referral Center), Waukesha, Wisconsin (Wisconsin Veterinary Referral Center), San Marcos, California (Veterinary Specialty Hospital - North County), Portsmouth, New Hampshire (Port City Veterinary Referral Hospital), Grayslake, Illinois (Premier Veterinary Group - Grayslake),

Orland Park, Illinois (Premier Veterinary Group - Orland Park), Chicago, Illinois

(Premier Veterinary Group - Chicago), Richmond, Virginia (The Oncology Service - Richmond), Honolulu, Hawaii, (Veterinary Emergency and Referral Center of Hawaii), San Diego, California (Veterinary Specialty Hospital - Sorrento Valley), Wheat Ridge, Colorado (Wheat Ridge Animal Hospital), Somers, Wisconsin (Wisconsin Veterinary Referral Center - Racine), Grafton, Wisconsin (Wisconsin Veterinary Referral Center - Grafton), Lawrence, Massachusetts (Bulger Veterinary Hospital), San Rafael, California (Pet Emergency and Specialty Center of Marin), St Paul, Minnesota (University of Minnesota), Columbia, Missouri (University of Missouri), Auburn, Alabama (Auburn University)

What is it? Ethos-PUSH embarks on a journey to improve the outcome of canine hemangiosarcoma by furthering our understanding of this disease. Dogs confirmed to have hemangiosarcoma will be randomized to receive 1 of 4 treatments. These treatment groups include standard therapies and novel therapies that have been selected as potential targets against previously defined genomic alterations in hemangiosarcoma. Treatment arms will be compared to determine a best protocol, which will serve as the benchmark for future treatment studies. Furthermore, tumor and blood samples will be collected and serve as platforms for nationwide collaborations to improve the molecular understanding of this disease and match molecular biomarkers with treatment response to specific therapeutics. This comprehensive approach is designed to bring about curative outcomes for dogs suffering from this aggressive cancer.

Data: None yet

Contact: Samuel Stewart,

CAR-T Therapy for Solid Tumors

Location: Urbana, Illinois

University of Illinois College of Veterinary Medicine

What is it? The purpose of this study is to investigate the safety and activity of genetically-modified immune cells (specifically chimeric antigen receptor T cells, CAR T cells for short) for specifically recognizing and eliminating tumor cells that express a specific surface protein called B7H3 when intravenously infused into pet dogs with spontaneous cancers. CAR-T therapies have been met with great success with human blood cancers and approved for human cancers, but not for solid tumors (for canines or for humans). Collaboration between Northwestern University and the University of Illinois. (Partially funded by CCA)

Data and Publications: Early publication (but without any clinical efficacy) can be found here

Contact: Rebecca Kamerer,


Location: Anywhere in North America

What is it? A drug that stimulates the immune system with active ingredients consisting of non-pathogenic bacterial cell wall fraction and nucleic acid.

Data: Small studies.

Contact: (613) 308-9788 or

Anything else? Immunocidin is fully approved by the USDA for mammary tumors. But bacterial therapy may help dogs with different types of cancer including osteosarcoma, transitional cell carcinoma, lymphoma, and hemangiosarcoma. Several successful case studies have been reported.

Contact Novavive and speak with Dr. Miriam Cervantes if you'd like to learn about their experience with hemangiosarcoma. (Partially funded by CCA)

Torigen Vaccine

What is it? Autologous vaccine created from dog’s own tumor cells. Conditionally approved by the USDA.

Data: Some published results for metastatic hemangiosarcoma

Contact: 860-519-9956 or

Location: Anywhere in the US. Make sure to contact them before surgery.

More information:

Questions? Email us at info@ccralliance

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All information the Canine Cancer Alliance website provides is for informational purposes only. It is not intended to be a substitute for professional veterinary advice. Always seek guidance from your veterinarian with any questions you may have regarding your pet’s health and medical condition.

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