While the ethics may be questionable, there is little in Canada to prevent people from killing their animals when they are no longer wanted, experts say.
The legal restriction is whether the animal is caused pain before it dies.
"You can kill your animal for whatever reason you want, because animals are considered chattel, provided that the method that you choose doesn't cause pain and suffering to the animal," said James Lawson, animal health officer with the B.C. SPCA, as other members of his organization continued their investigation into the shooting deaths of at least 70 sled dogs in Whistler, B.C.
The SPCA has said the cull in Whistler - in which dogs were killed in front of other animals and some apparently did not die instantly - may be illegal. But some situations in which a healthy animal is killed are above-board if the animal is not made to suffer.
David Fraser, an animal welfare professor at the University of British Columbia, argues that animal cruelty legislation should contain more specific rules on what constitutes humane euthanasia and what doesn't.
While some provinces (New Brunswick, for instance) make reference to the guidelines, others (like British Columbia) don't, compelling prosecutors to prove that an animal suffered unnecessarily, Prof. Fraser said.
"The court would have to be persuaded that distress was caused," he said.
What also bothers some animal advocates is that there is little restriction on the situations in which a dog can be killed, allowing businesses and individual citizens alike to put down healthy animals.
"It ought not to come as any surprise that this is the approach that was taken for these dogs. The fact that people are outraged makes me feel good, and I think begins to raise the spotlight on this issue," said Liz White, a director of the Animal Alliance of Canada. "But I suspect it will just go away until another incident happens, because it's very difficult to get legislation in Canada that deals with these issues."
She argues animals should only be killed if they have an incurable disease or injury, and that they should be euthanized by a veterinarian who sedates the animal beforehand.
Prof. Fraser also opposes killing healthy animals, but said that if it is done, procedures for ensuring the animal doesn't suffer, such as those set out by the CVMA, should be followed.
With a report from Caroline Alphonso
Editor's Note: The Canadian Veterinary Medical Association does not have guidelines on how to use a gun to euthanize dogs. Incorrect information appeared in the original newspaper version of this article and an earlier online version. This online version has been corrected.