Propranolol is typically used as a heart medication for humans and to treat vascular tumors in children. Abigail Martin, the Co-Lead Investigator and a second-year cardiology resident at the Atlantic Veterinary College (AVC), said there is promising indications that the drug could also help canines. “This medication has shown to actually shrink or completely get rid of these tumors in children,” Martin told CBC News.
“So our thought process is that if it works for kids, then we are hoping to look to see if it works the same for dogs, ” she stated. Propranolol is also used to treat a few other conditions like high blood pressure and abnormal heart rhythms. However, it is the similarities between vascular tumors in kids and canine heart tumors that make researchers think it will be effective. “They actually have very similar mechanisms on how they are grown,” Martin said. “Obviously one being more malignant and cancerous, the other one being more benign, but research has really shown promise to say maybe we should look into this a little bit more.”
Tumors common, but hard to treat
Martin said heart tumors in dogs are “surprisingly more common” than she expected when she first got into Veterinary Medicine. “The first few years I was a bit shocked to see how many patients I would see come in on emergency with the diagnosis of the fluid around their heart and then finding out that they have these heart tumors,” she said. “It is not something that is rare.”
However, many dogs do not present with symptoms until the tumor has become a major issue. “A lot of the time dogs can have these tumors and never know,” Martin said. “So they never show any signs of illness or they go on living their normal lives until it becomes an emergency.” At that point, there are not many treatment options other than palliative care to make the dogs more comfortable. And the treatment options that do exist, like surgery or chemotherapy, are prohibitively expensive. “The encouraging aspect about propranolol for these patients is that it is actually a fairly cheap medication,” Martin said.
‘We’re happy to see them’
Because dogs with heart tumors usually do not present with symptoms early on, Martin said it might be hard to find participants for the study. “We know that these cases are being seen around all clinics, emergency clinics and primary care clinics as well,” she said. “If owners are interested in pursuing … alternative options for these patients, then we are happy to see them.”
The college is encouraging dog owners who think their pets might benefit from the study to consult with their veterinarian. If they are enrolled, the dogs will receive the trial medication orally at home for one (1) month, with ongoing monitoring by the AVC’s Veterinary Specialists. This study will be the first time propranolol is used specifically to treat canine heart tumors, said Martin; however, if it shows promising results, it could also be tested for treatment of other types of cancer.
REFERENCE: CBC News (Canada); 01 SEP 2024; Victoria Walton