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The bond between Amy Amos and her 9-year-old bullmastiff, Phina, runs deep.

Through multiple health challenges since puppyhood, their connection has only strengthened. Now facing a terminal bone cancer diagnosis, they've embarked on a journey that prioritizes quality of life while potentially helping countless other dogs through innovative research.

"She's been through so much already," said Amos, watching Phina comfortably navigate the halls of Virginia-Maryland College of Veterinary Medicine. "I wanted to make sure she could have a good quality of life without pain for whatever time she has left."

Exploring comfort-focused alternatives

Rather than pursuing aggressive surgical intervention, Amos learned about a clinical trial at the veterinary college on Virginia Tech's Blacksburg campus, investigating histotripsy combined with immunotherapy as an alternative approach for dogs with bone cancer, or osteosarcoma.

"We're going to monitor her over time to look at the effects of histotripsy plus immunotherapy," said Joanne Tuohy, associate professor of surgical oncology at the veterinary college. "For this particular study, we will do histotripsy up to five times to enable treatment of the majority or all of the tumor because a lot of these dogs come to us with very large tumor volumes, and we can't realistically and safely treat all of it in one session."

Histotripsy uses focused ultrasound to target and destroy tumor tissue without traditional surgery, potentially reducing pain while stimulating the immune system to recognize cancer cells better.

"We are asking questions such as how the histotripsy treatment affects the pain of the tumor—whether it affords any pain relief, effects on the patient's quality of life, and whether the combined treatment of histotripsy and immunotherapy is stimulating the patient's immune response," Tuohy said.

Defined by resilience

From her earliest days, Phina has demonstrated resilience. Born with an esophageal stricture—a severe narrowing that prevented normal feeding—she required specialized intervention at the college's when just 3 weeks old.

"They didn't think she would make it because she couldn't get enough nutrition," Amos said. "It was so narrow that even milk would barely pass through. I had to hold her upright for anything to go down."

Despite these challenges, Phina thrived. But again, at age 5, she had emergency surgery for gastric dilatation-volvulus, a life-threatening condition also called bloat in which the stomach is full of gas or food and becomes twisted.

Through it all, her playful, affectionate spirit remained.

"She doesn't let anything slow her down," Amos said. "She's my Velcro dog—we're pretty tight and connected, and she loves being close. We've grown really close from having to hold her when she was a baby. She's been a blessing to our family."

A difficult diagnosis

When Phina began limping in February, Amos' experience as a former radiologic technologist at the veterinary college triggered immediate concern, especially after noticing a lump on Phina's shoulder.

"When she started limping, that was in the back of my mind because two of her siblings had the same thing," Amos said. "I started seeing a knot on her shoulder. When she stood up to eat and turned her head, I noticed a spot, and when I touched it, she didn't like it. That's when I knew I needed to have my vet check higher up."

The diagnosis confirmed her fears: osteosarcoma in Phina's left shoulder blade, or scapula.

The standard treatment— amputation followed by chemotherapy—presented significant challenges. Amos worried about her quality-of-life post-surgery.

"It was a tough decision to try to make," Amos said. "She's 9 years old and has some arthritis already. Being a bullmastiff, she's big, and with arthritis in her other shoulder, putting all her weight on just one side would be difficult."

The treatment experience

Phina underwent two histotripsy treatments targeting different areas of her tumor. During her second treatment, she also received an immunotherapy injection designed to enhance her immune response.

"At the last histotripsy treatment, she got the injection of the immunotherapy into that treatment site to help augment an immune response," Tuohy said. "Her tumor is somewhat atypical since it's on the scapula rather than the long bones where we typically see osteosarcoma, but we were pleased with how much of the tumor we could treat."

Following treatment, Phina experienced a few expected difficult days but soon returned to her usual, spirited self.

"After the first treatment, she did have a couple of rough days," Amos said. "She wasn't herself and was kind of pitiful for a few days. But after that, she started perking back up and was pretty much her normal self again. She still has a little bit of a limp, but her quality of life is better than before."

Comprehensive monitoring and care

With the initial treatments complete, Phina's care now shifts to careful monitoring to track her progress and response to the therapy. Two weeks post-treatment, Phina returned for her first follow-up evaluation, beginning a series of comprehensive check-ups designed to assess both her comfort and the treatment's effectiveness.

"We send validated quality of life and pain surveys home with the families for them to fill out each week," said Tuohy. "We also assess them with the gait analysis downstairs for objective measures of how much pressure they're putting on their limbs."

Additional monitoring includes MRI scans to evaluate changes in the treated tumor area, thoracic radiographs to check for metastasis, and blood samples to assess immune cell activation.

"The blood samples help us evaluate the immune cells and determine whether they appear activated," Tuohy said.

Contributing to a greater purpose

For Amos, participating in the clinical trial serves a dual purpose—helping Phina live her remaining time comfortably while potentially benefiting other animals facing similar diagnoses.

"Part of the reason I did it was because it furthers the research and helps them develop things that might help other dogs," Amos said. "I know how much they learn here, and I love that they do research. It also transfers to human medicine eventually, which is really meaningful."

The research team hopes these efforts will eventually lead to better treatment options for dogs with osteosarcoma.

"If we could offer histotripsy as another treatment option, that would be great," said Tuohy. "The intent is to spare patients from needing an amputation because if we could destroy the cancer cells in situ and let the bone heal, then we don't have to have an amputation done. And at the same time, if we can stimulate the immune system and activate a better immune response, that would be fantastic as well for mitigating metastatic disease development.

"Part of the problem with osteosarcoma is that it wants to metastasize. So despite amputation and chemotherapy, which are standard treatments, patients ultimately will still experience metastasis. The chemotherapy simply delays it. So if we can improve survival in these patients using histotripsy combined with immunotherapy, that would be wonderful as well."

Living each day fully

For now, Phina continues enjoying life at home in Peterstown, West Virginia, with Amos and her family, receiving plenty of love and attention.

"She's 9 years old, and at first, they didn't even think she would make it past those early weeks," Amos said. "She's lived her life to the fullest. I mean, she hasn't let anything slow her down. She was resilient about it even as a puppy—she bounced back quickly. I hope I've given her a good life. Every good day we have now is a gift."

Research powered by community support

For more information about clinical trials or cancer treatment options for your pet, please contact your local veterinarian or browse current studies on the Virginia Tech Clinical Trials .

This study is especially meaningful because the osteosarcoma research began with support from the Veterinary Memorial Fund—a program powered entirely by the generosity of the community. What started as a locally backed effort has since grown, drawing the attention and support of major organizations like the Focused Ultrasound Foundation, National Institute of Health, AKC Canine Health Foundation, and numerous dedicated individuals.

It's a powerful reminder that when communities come together—even in memory and hope—they can spark breakthroughs that reach far beyond what anyone imagined. If you'd like to make a lasting impact in a dog's life—just like Phina's—please visit our giving page and be part of the next breakthrough.