Texas A&M testing nonsurgical alternative to treat disc herniation in dogs
When Oscar, a five-year-old dachshund, developed partial paralysis from a herniated disc, his owner, Ashley Williams, expressed concern to her veterinarian about being able to afford the surgery.
Her vet put her in touch with Nicholas Jeffery, BVSc, PhD, MSc, a professor of small animal clinical sciences at Texas A&M’s School of Veterinary Medicine & Biomedical Sciences (VMBS).
Jeffery, an expert in spinal cord injury, has been looking for a nonsurgical method of treating disc herniation in dogs for several years now. He was motivated in part because of the prohibitively high cost of traditional surgical treatment, which can run as high as $12,000 in parts of the US.
“[The cost] of the traditional imaging and surgery makes it inaccessible to a lot of pet owners.”
He saw an opportunity when doctors in Japan pioneered a nonsurgical—and far less costly—treatment for disc herniation in humans that involves injecting an enzyme into the affected disc to dissolve and digest the ruined tissue. This specific enzyme has been patented and approved for use in humans in Japan, and it’s expected to be approved for human use in the US in the not-too-distant future.
Disc herniation 101
“[A spinal] disc has a lot of fibrous tissue on the outside of it, and then it's got a jelly-like bit in the middle,” Jeffery explains. “It’s a little like a jelly donut but the outside is really quite tough and fibrous.”
In the case of a herniated disc, the fibrous tissue on the outside breaks down and weakens until eventually the jelly-like bit in the middle—which has also deteriorated—can force its way out between the fibrous tissue.
Disc herniation in humans tends to affect the nerve roots in the caudal lumbar/lumbosacral area, Jeffery said, whereas disc herniation in dogs tends to occur more proximally and affect the spinal column itself.
In dogs, it can lead to hind limb paralysis and incontinence; and surgical intervention is the standard method of treatment.
“Human spinal discs tend to sort of bulge up rather than ‘explode’ [like canine spinal discs],” Jeffery said, his understated British accent making everything he says sound a little laconic. “That can happen quite suddenly, and it can come out with a lot of force. Then it hits the spinal cord and that creates a lot of inflammation.”
Oscar kicks off the clinical trial
In September 2022, Jeffery launched a clinical trial to test the treatment on 30 small dogs under the auspices of the VMBS Office of Veterinary Clinical Investigation (OVCI).
Oscar became the first dog enrolled in Jeffery’s clinical trial, which uses a version of the same enzyme used in the Japanese human studies. Oscar came into the hospital, received his injections, and was back home the next day.
Although the enzyme digested Oscar’s herniated disc in a matter of hours, it took about three weeks for his spinal cord to recover enough for him to walk again—roughly the time it would have taken after surgery.
The standard of success of a surgical intervention is walking 50 steps (or about 40 feet) without support. Oscar passed with flying colors.
“I think we can say he had a successful outcome,” said Jeffery.
“Part of what we're doing is accumulating evidence about safety and efficacy,” he said—data he will share with the FDA once the trial concludes. “That might lead to licensing of the enzyme for use in dogs.”
While Jeffery couldn’t estimate the cost of the injections if the treatment is approved, he said it would be considerably less than the surgical alternative, as only a few injections at most would be needed and it could be done as a one-time outpatient procedure.
“The important thing is that we're doing it without having to go through a lot of in-depth imaging like MRI scanning, which costs a lot of money.” Never mind the cost of the surgery itself, or boarding the patient during recovery.
“It all adds up,” said Jeffery. “Whereas what we’re doing is very noninvasive because, basically, we’re just using needles.”
Another cost-saving advantage should the treatment become available: Jeffery said pet owners likely wouldn’t need to go to a specialist to have it done; it’s simple enough that general practice veterinarians might be able to do it—with a little training.
“You have to have some idea of the three-dimensional anatomy to do it. I'm familiar with it from doing spinal surgery but a lot of primary care vets won't be,” he said. “But I don't think there's a reason why they shouldn't be able to learn to do it.”
The clinical trial is ongoing and currently has 10 dogs enrolled out of a possible 30, but Jeffery has his sights set higher than that: “If we don’t come across any adverse effects, then I’ll probably try to increase that to at least 50.”
He’s also trying to run some mirror trials in Britain but says that’s not going quite as smoothly. “The regulations there are a little more complicated to deal with,” he adds . . . laconically.
“One of the things that's difficult about these studies is always knowing how much to attribute to the new treatments and how much to attribute to some natural improvement you can get anyway,” he said. “So, I don't want to over-claim how fantastic this is until we've completed the study and compare [our outcomes] with surgical outcomes to see whether we’re getting close to the surgical benefits or not.”
But Jeffery can’t contain his optimism.
“I've been really pleased with the outcome so far. Partly because the dogs have been doing well and partly because they just look so happy afterwards. It’s such a benign procedure to put needles into the spine compared to doing surgery, and the recovery is very quick.”
“Even the same day after we've done this, we've got dogs that are coming out of their cages, wagging their tails,” he said. “They just look very relaxed about having it done.”
Despite the rosy early results, Jeffery cautions against getting too excited about the treatment: “Even once the trial is completed, this could not become a procedure until such time as the enzyme is approved for pets by the FDA.”
Nevertheless, Jeffery hopes the data his team collects will help make that happen.
“It would be fantastic if we could get to that stage.”
For once, Jeffery’s accent is neither laconic nor understated.
And he says it again: “It would be fantastic!”
Veterinarians and dog owners can learn more about the clinical trial here.
Tony McReynolds is a temporarily petless freelance writer who lives near a dog park in Lafayette, Colorado. He dreams of one day owning a Newfie who isn't afraid of water (which the last one was, and seriously, how is that even possible?).
Photo courtesy of the Texas A&M School of Veterinary Medicine & Biomedical Sciences
Disclaimer: The views expressed, and topics discussed, in any NEWStat column or article are intended to inform, educate, or entertain, and do not represent an official position by the American Animal Hospital Association (AAHA) or its Board of Directors.