Dogs with spinal cord injuries may soon benefit from an experimental drug being tested by researchers at the University of California, San Francisco (UCSF) and Texas A&M College of Veterinary Medicine & Biomedical Sciences — work that they hope will one day help people with similar injuries.
Funded through a three-year, $750,000 grant from the U.S. Department of Defense, the drug to mitigate damage has already proven effective in mice at UCSF. Now the Texas team will test how it works in previously injured short-legged, long torso breeds of dog like dachshunds, beagles and corgis, who often suffer injuries when a disk in their back spontaneously ruptures, damaging the underlying spinal cord.
About 120 dogs a year that develop sudden onset hind limb paralysis after such injuries are brought to the Small Animal Hospital of Texas A&M University, where they receive surgical and medical treatment similar to that for human spinal cord injury. Now, researchers will test whether the new treatment works on some of these dogs, with their owners’ consent.
“It would be phenomenal if it works,” said Linda J. Noble-Haeusslein, PhD, a professor in the UCSF departments of Neurological Surgery and Physical Therapy and Rehabilitation Science who designed the intervention. “We are in a unique position of being able to treat a dog population where there are simply no current therapies that could effectively improve their hind limb function.”
The new treatment does not seek to regrow injured pathways in the spinal cord. Instead, it aims to mitigate damage secondary to the spinal cord injury. Most spinal cord injuries trigger a cascade of chemical reactions in the spinal cord that collectively damage nearby cells and pathways, contributing to functional deficits including hind limb function.
A few years ago, Noble and her UCSF colleague Zena Werb, PhD, showed how blocking the action of one protein found in the spinal cord of mammals can help mice recover from spinal cord injuries. This protein, called matrix metalloproteinase-9, can degrade pathways within the cord and cause local inflammation, leading to cell death.
The injured dogs offer a great opportunity to take the next step on this treatment because their injuries more closely mimic spontaneous human spinal cord injury and, as is the case with humans, no existing treatment has substantially reduced paralysis.