Just to clarify, serving horse meat in Quebec is legal and a horse steak is a delicacy. The issue is that race horses tend to be shot full of steroids (to deal with joint inflammation, not to improve performance) and painkillers near the end of their racing careers.

The term “put out to pasture” is mostly a euphemism to keep people from getting to upset about it. A few do, but not many. It just costs too much money to keep a barn warm in winter and the horses fed. The owners have enough trouble keeping the active racers fed, with the province phasing out horse racing with ever fewer races each year.