A one-size-fits-all approach is not ideal for treating dogs with spinal cord injuries, according to a clinical trial conducted at the North Carolina State University’s College of Veterinary Medicine. The findings may lead the way to personalized treatments for spinal cord injuries, and hopefully better outcomes for canine and potentially human patients, the college noted.
The study included 19 paraplegic dogs, all of which had suffered similar spinal cord injuries. All dogs had been injured long enough to rule out any hope of unaided recovery.
Two drugs were used in the study: 4-Aminopyridine (4-AP) and a derivative of the drug called t-butyl, which was developed by Daniel Smith and the Center for Paralysis Research at Purdue University. 4-AP has been tested on humans for spinal cord injury, and is currently in use as a treatment for multiple sclerosis. T-butyl has not been tested clinically on humans. Both drugs work by helping damaged nerves transmit signals, according to the college.
The trial was a blinded, placebo-controlled, cross over study. All dogs were treated with a placebo and both drugs, each for a two-week block of time assigned randomly, to first determine whether the drugs were effective, and then see whether or not there was a difference in efficacy between the two medications.
The study showed that there was little difference in efficacy between the drugs themselves. Both drugs produced a significant improvement in stepping when compared to placebo. However, the difference in levels of response from the dogs in the trial ranged from no improvement to being able to take unassisted steps on a treadmill.
“The question quickly went from ‘Do the drugs work?’ to ‘Why aren’t they having similar effects across the board?’” said Natasha Olby, VetMB, Ph.D., professor of neurology at NC State University’s College of Veterinary Medicine, who led the clinical trial. “And there are many possible factors to consider—some of the dogs may not have any axons left for the drug to act on, or it may depend upon how long they’ve been paralyzed or even whether or not they have a genetic predisposition to respond to this treatment.”
Dr. Olby is now directing her attention to identifying patient populations that will respond best to the treatment.
“There is no doubt that either or both of these medications can have an amazing effect on the right patient—but now we have to do the work of finding out what conditions make a patient the right one. If we can do that, we may save both patients and owners a lot of unnecessary frustration.”
The study appeared online in late December in PLOS One.