“I love the fact that it may help humans someday.”
After finding out that his 10-year-old Munsterlander had a tumor on his jaw, opting for a new $8,000 surgery to remove part of the lower jaw, then seeing Whiskey become the face of the ground-breaking procedure, that’s what Tom Swierk, Whiskey’s owner, has to say.
It was just before Thanksgiving 2011 when Swierk noticed that three of the dog’s favorite chew sticks had collected on the living room rug. “I thought it was a rotted tooth,” he recalls thinking.
He took Whiskey directly to Pets Unlimited, 24-hour veterinary clinic in San Francisco, where Swierk lives with his partner Robin Addams and their 7-month-old Cocker Spaniel, Kahlua. After examining Whiskey, “I’m so sorry” were the first words out of Polly James, D.V.M.’s mouth, Swierk says.
“I knew at that point that we were up the creek.”
Whiskey had a malignant tumor that had invaded his lower left jawbone.
James shaved down the growth a bit to stabilize it, Swierk says. By that Sunday, they had the results from the tests James ordered on the tissue.
“I pretty much begged her to find out where we could go and what we could do to get him the best medical treatment,” Tom says.
To even have a chance of surviving the cancer, Whiskey would need part of his jawbone removed. Until recently, no proven options existed for bridging the gap where the bone would be cut out. His jaw would not function normally, and his mouth would not look the same.
“Formerly, when we had to remove a portion of the bone we were forced to leave the defect in the jaw because there was no better alternative,” says Frank Verstraete, Dr.med.vet, a diplomate of the American Veterinary Dental College and professor at the University of California, Davis, School of Veterinary Medicine. Verstraete heads up the dentistry and oral surgery at the UC Davis’ William R. Pritchard Veterinary Medical Teaching Hospital, and one of his interests is tumors just like Whiskey’s. Although the condition is not life-threatening, he says, the dog’s jaw is never quite the same again, and frequently the dog’s teeth damage the roof of the mouth and cause ulcers in the mouth.
Dogs can lose jawbone following an injury, but it’s more typically removed surgically due to an invasive tumor. UC Davis reports that soft-tissue tumors – including the squamous cell carcinomas responsible for 70 percent of all oral tumors in humans – frequently appear in dogs’ mouths and grow into the bone.
After giving Tom and Robin the news, James called nearby UC Davis on Monday to discuss Whiskey’s case. “On Tuesday, I called and pretty much begged them to see Whiskey,” Tom says.
“Some dogs can go years with just having the growth shaved,” Tom says. “But because Whiskey’s growth was so close to the lymph nodes and because this type of tumor metastasizes about 10 percent of the time, there was a higher likelihood that it could happen to Whiskey.
“I like to think of it as Whiskey had a tumor and, in order to make his quality of life as good as it had been, we were willing to take that risk. We thought that he was getting robbed by having this growth. I thought he was getting shortchanged.”
A week later, they headed to Davis. During the surgery, more than half of his lower left jawbone was removed. “We had not an ounce of reservation about doing this procedure. We knew dogs before him had had the surgery successfully. We knew that the odds were very positive. We just knew he would do well because when he was less than a year old, he swallowed a ball.” It required a 10-inch incision to remove the ball from Whiskey’s stomach.
This time, Whiskey was the beneficiary of a joint project between UC Davis biomedical engineers and veterinary surgeons who thought several years ago that it might be possible to regrow a missing section of jawbone by screwing a titanium plate across the gap, placing a stiff, sponge-like scaffold of sorts in the gap, which was soaked in bone growth-promoting proteins.
The scaffold material and bone growth proteins were donated by Pfizer Inc. to the UC Davis research team for “compassionate use in animals,” as permitted by the U.S. Food and Drug Administration.
Those proteins stimulate the dog’s remaining jawbone to grow new bone cells, Verstraete explains, eventually filling the entire defect and integrating with the native bone. The 60-pound dog is one of eight over the last two years who have essentially grown new jawbone after having the procedure.
Whiskey remained in the hospital for 24 hours after his surgery. “They prepared us for his mouth to be quite swollen,” Tom says, but it was only about a half-inch bigger than usual. By the time they took him home, he was eating bits of soft food out of the doctor’s hand, Tom says.
When they got him home, the only way to tell he’d had surgery was a shaved area for a morphine patch, the cone Whiskey had to wear and a little bit of shaving around his mouth.
“Within two weeks after the procedure, you could feel bone forming under the skin, and by three months we had new bone that was very similar in density to that of the native bone,” biomedical engineer Dan Huey says.
Four weeks after the surgery, Whiskey was jogging through the streets of San Francisco, Swierk says. The dog had never joined Swierk in the past, but Tom says he “just knew” that Whiskey needed to be “active and vibrant, and it would keep his energy up.”
From December 2011 through February 2012, Whiskey ate only soft food – tuna and salmon, and lentil and garbanzo beans. During March, he started on his kibble again. In April, he was able to eat one of his favorite treats – raw cauliflower. He could have raw carrots again in May, and by June he was chewing on a small soft tennis ball. “He’s now totally chasing his balls, eating his dollies,” Tom says.
Although he is missing the teeth that were in the removed jawbone, he hasn’t lost any others, something that can happen within the first three months after surgery. Whiskey goes in for X-rays and blood tests every six months, but other than that, it’s life as usual.
Whiskey was the sixth of eight dogs successfully treated with the new procedure and had the largest section of bone removed. All of the dogs are “alive and doing fine, with well-formed, functional jawbones,” according to UC Davis.
The research team, which also includes veterinary surgeon Boaz Arzi, is preparing a manuscript for submission to a scientific journal. They’re also planning to modify the current technique to use in larger jawbone defects.
According to UC Davis, the treatment not only offers hope for dogs and other animals, but also will likely provide valuable information for human medicine.
“I think that for anyone who has a dog that qualifies for the procedure, it’s a no-brainer,” Swierk says, assuming the financial resources are there. “Whiskey’s quality of life has been sustained the entire time. The only thing that’s different is that I never used to jog with him, and now I do.”