BY KIRSTEN ANDERSON SPARK PROGRAM
The ritual of dog walking creates a special bond between owner and pet, keeping both active and healthy. But many dogs fall victim to lameness due to aging or traumatic injury. Now, Ontario Veterinary College researchers hope to make things more comfortable for the animals. They're testing whether a modified treadmill can help them develop and evaluate lameness treatments for dogs.
Lameness can be difficult to assess visually, says Prof. Noel Moens, Clinical Studies. Although it may be obvious that the dog is lame, it's nearly impossible to determine how much weight a dog is actually placing on each foot something veterinarians need to know when they're treating lameness.
That's why he's leading a research team to analyze gait in dogs, using a novel technique where force plates metal plates that can measure the force and angle of a footstep are built into the base of a treadmill.
If this technique proves to be useful, it could provide a new means of evaluating lameness treatments for dogs, such as surgical procedures and pain or arthritis medication, says Moens.
Force plating allows us to quantify the amount of lameness in dogs, he says. By incorporating it into a treadmill, we're able to record several consecutive footsteps, something that would have been difficult for us to do before.
Here's how it works. Dogs are walked at a constant speed on a special treadmill outfitted with two force plates, one located behind the other. When a dog steps on the force plate, a computer records the amount of force and direction applied by the animal's foot. From there, researchers can analyze the dog's gait and determine whether or not the animal is lame, which leg is weakest and a specific treatment's effectiveness.
Traditional force plating is considered to be the gold standard for gait analysis. In this technique, researchers walk a dog back and forth over a force plate in the floor to obtain gait data. But there are several drawbacks, says Moens. First, to obtain reliable data, only one foot can land on the plate at a time. In addition, changes in body posture and speed both factors that are difficult to keep consistent can affect the results. And in some cases, it can take researchers up to an hour and a half of walking a dog back and forth over the force plate to obtain sufficiently good data to make a useful assessment, he says.
By incorporating force plates into the floor of the treadmill, Moens has been able to eliminate some of these variables. Using a treadmill means researchers can keep the dog's walking speed constant for each trial. And by using two plates, they can obtain data from both a front foot and a hind foot simultaneously, which saves time and allows several consecutive footsteps to be recorded in a short period.
Preliminary results are promising. In one trial using eight dogs, Moens and his colleagues found they were able to obtain enough data in a much shorter time frame. And in one animal, they picked up lameness they hadn't observed initially, indicating how sensitive this technique can be.
It can allow us to find lameness in dogs that we normally may not be able to catch visually, he says.
The next step for Moens and his research group will be to assess a larger number of dogs with the treadmill to determine its effectiveness in different situations. They will also test dogs already diagnosed with lameness to see if they can obtain similar results.
This study was sponsored by OVC's Pet Trust.
