A century ago, a man invented a mechanical hare and opened up a dog racing track in California. Tracks opened up in several states (especially Florida), and most English speaking countries. Recent extension of casinos and other forms of gambling has closed many American tracks; but the industry still exists.
The business needs young fast dogs, always more. If they are not young and fast, they are discarded, and replaced; very much like human labor.
Now, in the recent past, many of the dogs were then put to death. Humanitarian dog fanciers began to organise greyhound rescue societies. The unemployed, and unemployable hounds that were born and bred to serve monetary interests have been sometimes saved to become companion animals.
Many realise that we are all creatures of the same God. Certainly, we know Francis of Assisi taught this. He is not the only patron of animals. There are saints for all animals, for domestic, for wild, for particular animals, for ill animals... The two Tonys (Egypt, Lisbon/Padua) are both animal patrons. Some animals have two patrons. Dogs have Hubert and Roch. We are to treat animals well. We have the custom to have animals blessed on the feast of Francis, 4th of October.