The Mason lab at the University of Pennsylvania School of Veterinary Medicine is investigating the possibility that a gammaherpesvirus can infect dogs and may contribute to lymphoma. The virus is thought to be highly similar to Epstein-Barr Virus that infects the majority of humans.

In most humans, infection is asymptomatic (no clinical signs), but in a very small subset of people, the virus is associated with lymphomas. Mason’s lab has shown that some dogs (like people) can be infected with an EBV-like virus and that this appears to be associated with lymphoma in some cases (Evidence of an oncogenic gammaherpesvirus in domestic dogs. Huang et al. Virology. 2012 Mar 7). 

Using a relatively simple blood test, Mason’s lab can determine whether dogs have been exposed to an EBV-like virus. They now aim to screen approximately 500 healthy Golden Retriever dogs between 6 and 8 years of age to determine whether they are infected with the virus. 

Participating dogs will be evaluated every 6 months for 2 years to determine whether the presence of increasing amounts of virus and antibodies to the virus predicts which dogs many go on to develop lymphoma. 

The study aims to provide very important information about a possible environmental cause of cancer and may lead to future anti-viral therapies for cancer. This study is supported by the National Institutes of Health.

We invite All Owners of Golden Retrievers to Take Part in This Study

All owners of healthy Golden Retrievers are invited to participate in an unprecedented study to investigate the possibility that a particular virus (a gammaherpesvirus) can infect Golden Retriever dogs and that this infection contributes to the development of lymphoma in some dogs.


If you have a healthy Golden Retriever dog that has not been previously diagnosed with cancer, and is between 6 and 8 years of age you may be eligible to participate in this study. Complete information regarding the study and study eligibility can be found on the consent form (download below).

Samples Required for the Study

The study involves taking a blood sample from your dog once every six months for two years.

If your dog develops lymphoma while on the study, a biopsy of the malignant lymph node tissue will be taken and used to confirm the diagnosis and determine whether this virus is involved in the tumor.

Blood samples and lymph node biopsies can be taken at your local veterinarian and sent to the University of Pennsylvania School of Veterinary Medicine.

About Costs: Please note that we do not have funds to cover any costs associated with visits to your veterinarian or costs associated with lymph node biopsies or blood samples. Funds are available to pay for shipping of samples to UPenn from your local veterinarian and for all laboratory tests that look for the virus in the blood and in any tumor tissue.

Study Participant Information for Golden Retriever Dogs

If you would like to participate in the study, please download:

the consent form (PDF)

the examination form and sample submission instructions (PDF)

Take these to your veterinarian. Please complete the consent form and ask your veterinarian to complete the examination form.

Both forms should be submitted to UPenn with your samples.

All samples should be sent overnight to the following address:

Attention: Dr. Nicola Mason

Room 335, Hill Pavilion

University of Pennsylvania School of Veterinary Medicine

380 South University Avenue

Philadelphia, PA 19107

Contact Information

Golden Retriever owners may also contact Rhonda Hovan (GRCA Health Committee member) by telephone at 330-668-0044 or 330-338-4236 (cell) or by e-mail at

Related Resources

Learn more about Dr. Nicola Mason

Golden Retriever Club of America P

Penn Vet Veterinary Clinical Investigation Center (VCIC)

Penn Vet Mari Lowe Comparative Oncology Center

If you would like to contribute to canine cancer research in the Mason laboratory, please send your check made payable to the Trustees of the University of Pennsylvania and note that it should be designated to the Mason Cancer Research Fund. Please mail to:

Office of Development

School of Veterinary Medicine

3800 Spruce Street, Suite 172E

Philadelphia, PA 19104

McMaster University Researchers in Hamilton, Ontario, Discover Drug that Kills Cancer Stem Cells!

The Spectator Newspaper, Hamilton, Ontario, Canada

Reporter: Joanna Frketich

McMaster researchers have discovered a drug commonly used for Parkinson’s Disease and schizophrenia kills cancer stem cells without the toxic side-effects of other treatments.

Patients taking thioridazine for Parkinson’s and schizophrenia have 10 times less instance of cancer after being on the drug for a few years.

“We’re connecting dots that we weren’t connecting before,” said Dr. Mick Bhatia, principal investigator of the study and scientific director of McMaster’s Stem Cell and Cancer Research Institute.

“We’re excited we have something interesting, but we’re always nervous because we want to make sure it helps people. The impact of this will be determined if we can put some patients in remission and certainly that’s my romantic goal.”

He expects a small number of Hamilton leukemia patients with no other treatment options will have access to the drug through a clinical trial within a year. He’s also hoping to set up a second trial at another Ontario cancer centre.

“It’s not everyday you find a drug you can move into the clinic,” said Bhatia. “The only thing we can hope for is that what we’ve seen in the laboratory, we’re hoping will work in a patient.”

If it works, it could dramatically change cancer treatment. Thioridazine on its own reduced leukemia stem cells by 50 per cent in 24 hours in mice injected with primary human samples, found the study published in the science journal CELL.

“That was quite surprising,” said Bhatia. “We have certainly not seen any drug we’ve tested have that kind of potency.”