Stories of progress, inspiration, and information in overcoming osteosarcoma.

Losing a Beloved Mastiff to Canine Osteosarcoma

Reno couple dedicates their lives to saving dogs from osteosarcoma after losing their beloved Lavinia to the “horrific” disease.

Growing up around Great Danes and horses, Robyn Roth has always had a soft spot for large animals. When she met Mack McKinley, she found someone who shared her vision and her deep love for animals.

The two married, and they worked hard at their day jobs — Mack as a juvenile detention officer and Robyn as a physical therapist treating both humans and animals.

In their spare time, Robyn and Mack devoted themselves to rescuing dogs of all shapes, sizes, and breeds, but Mastiffs became their personal breed of choice. Over the years, they outgrew their space, and so they left their California home to open a 50-acre ranch outside Reno, Nevada.

Building Sugarland Ranch from the Ground Up

Sugarland Ranch opened in 2004 — part dog rescue and part dog boarding facility, which helped fund the rescue’s mission.

Since opening the 8,500-square-foot structure they built from the ground up, Robyn and Mack have taken in hundreds of dogs. And canines are not the only beneficiaries of their work. They have also played monumental roles in the lives of humans. During the Afghanistan War and Operation Iraqi Freedom, Robyn and Mack looked after dogs belonging to service members who would have otherwise had to surrender their pets during deployment. And they did so without charging the service members.

“We would take the dogs in for the length of their deployment, and then when they returned, they had a nice warm welcome home from their pups,” Mack says. “We did that for approximately 22 GIs over the years, and luckily all of them returned home safely.”

The couple offered the same service to domestic violence survivors fleeing to shelters that did not accept pets until other nonprofits established programs addressing this need.

Lavinia Enters Their Lives

In 2011, Robyn and Mack received a call from a California physician-researcher who had been breeding Neapolitan Mastiffs. The breeder was reportedly in financial trouble and asked if they could take some of his dogs.

And so the couple rented a van and loaded it with dog crates to relocate the dogs — a total of 12 coming over to their ranch. That is when they met Lavinia.

“At first, she was loud and unruly, but she turned out to be the love of our lives,” Robyn says. “There are just some dogs that are heart dogs, and Lavinia was one of them.”

“At first, Lavinia was loud and unruly, but she turned out to be the love of our lives. There are just some dogs that are heart dogs, and Lavinia was one of them.” — Robyn Roth

Lavinia and the others had multiple health concerns, such as dermatological and eye conditions, requiring multiple veterinarians to provide care. All required neutering or spaying as well as laparoscopic gastropexies (tacking the stomach to the abdominal wall) to prevent gastric torsion in the future, a potentially fatal condition known to Mastiffs and other big-chested breeds. Robyn was already in the process of retiring her animal physical therapy private practice; in order to accomplish all the care required, she negotiated with a veterinarian colleague to transfer the therapy practice to the animal surgeon in exchange for some of the care required to treat the dogs.

While it has never been confirmed, Robyn suspects the physician-researcher had been utilizing the dogs as part of his cancer research, because every one of them ended up with some form of cancer, some with what appeared to be similar to types of cancer he was researching.

Robyn Roth and Mack McKinley's mastiff Arianna


In October 2017, Lavinia’s half-sister Arianna was diagnosed with osteosarcoma after showing lameness in her right forelimb, a tell-tale sign of bone cancer in a dog’s leg. Due to a pre-existing heart condition that made it risky for Arianna to receive repeated anesthesia, radiation therapy was not an option. They tried bisphosphonate infusions, but Arianna did not respond. She died three months later.

By April 2018, Lavinia began showing the same lameness.

“We rushed her in for imaging, but I already knew,” Robyn says. “It was in the exact same spot as Arianna’s cancer.”

But unlike Arianna, Lavinia did respond to the bisphosphonate — for several months, anyway. Her bone cancer symptoms had all but disappeared. Then, in December, they returned suddenly, and Lavinia’s health took a nosedive. She died on Dec. 28, 2018.

A Difficult Loss

Lavinia’s death left a sizeable hole in Robyn and Mack’s hearts. The ranch’s clients mourned as well.

“Lavinia used to be the greeter in our front office, and she would know when people had dog cookies with them. She would go into their jackets, putting her head in their pockets,” Robyn says. “After a while, people started baking treats especially for Lavinia. Everybody loved her.”



Lavinia had also made quite an impression on the staff at Vista Veterinary Specialists in Sacramento, California, where she received her canine bone cancer treatment. Less than a month after Lavinia passed, Robyn and Mack received a letter from Ethos Discovery, a veterinary cancer research organization, notifying them that the team at Vista had made a donation in Lavinia’s name. The letter was signed by Ethos Discovery President and Director Chand Khanna, DVM, PhD, a veterinary oncologist and renowned researcher in the field of osteosarcoma who also serves on the Strategic Advisory Board of the Osteosarcoma Institute (OSI).

“We do a lot for other people, but that donation was something that was done for us,” Robyn says. “It touched us very much.”

A few months later, Robyn came across Dr. Khanna’s name again. This time it was on the TV show 60 Minutes.

“They were talking about osteosarcoma research and mentioned Dr. Khanna,” she says. “Then they mentioned the Osteosarcoma Institute. That is how we got introduced to the work the OSI does.”

A Huge Need for Canine Osteosarcoma Treatment Options

Osteosarcoma is 10 times more common in canines than it is in humans, and large-breed dogs are at the highest risk. Still, treatment options remain limited and expensive. And when it comes to palliative care for canines, the options are limited, essentially boiling down to oral NSAIDs and other pain management drugs of questionable effectiveness for canines. Owners typically opt for euthanasia.

“We need more options in treatment and palliative care,” Robyn says. “Even better, we need a vaccine to prevent osteosarcoma in the first place.”

Such therapies are in the works. In fact, in the 2022-2023 grant cycle, the OSI awarded funding to researchers working on immunotherapy for canine patients. Given the similarities between osteosarcoma in humans and canines — which include what the disease looks like at the cellular level and how it metastasizes — the hope is that research being done for dogs will ultimately lead to advances for osteosarcoma care in humans.

Advice for Pet Owners

In the meantime, Robyn strongly recommends pet insurance (her personal choice is Trupanion), and going to a board-certified veterinary oncologist any time a pet displays signs of osteosarcoma, namely lameness.

“Not all primary care veterinarians take the option of referring out to a veterinary oncologist and may try to manage this disease themselves. Alternatively, an owner may not have the financial resources to follow through with a specialist,” Robyn says. “Any veterinarian can set up a chemo lab (pending each state’s practice acts) and administer chemo, which may interfere with other treatment choices recommended by a boarded veterinary oncologist.”

Robyn and Mack are hopeful that there are better treatments out there for canine osteosarcoma — even if discovered after their lifetime. When they learned about the OSI’s work, Robyn and Mack decided to earmark a portion of their estate for the OSI upon their passing. “In our early years with our Mastiffs, one developed mast cell cancer and ultimately died. Now there are aggressive treatments for mast cell and dogs can survive,” Robyn says. “We strongly believe that the same advancements can be made with osteosarcoma, and this is why we have elected to firmly support the OSI and the critical work they are doing so humans and dogs do not have to suffer.”

“We want to ensure that the assets we have developed are distributed to secure organizations like the OSI who will continue our mission long after we are gone,” Mack says. “We have lost so many of our beloved pups to cancer. We are thrilled to have discovered the OSI and we know that they will be there to continue the research and find a preventative route and a cure for osteosarcoma.”

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