I volunteer for a local adoption (mostly) greyhound adoption group. The hounds that find their way into our adoption group can come from the track, from an owner whose health has made it difficult to care for their hound, or from a shelter. Often the hounds that find their way to the shelter are sighthound mixes.
Sighthounds can have a high prey drive. We do a quick test to see how they react to a cat-shaped toy and, if available, a very patient testing cat. Those who pass aren't necessarily ready for the cat life, but they are ready for our Kitty Boot Camp. They'll get used to home life and living with cats ... we hope. Not all graduate. Some may not have a prey drive right off, but some develop it later or develop a "play drive". Neither are healthy for the cat.
If they get used to my cats and can be trusted, they're ready for their new home. Not all will end up spooning and being the ideal hound-cat social media phenomenon, but many end up happily ignoring their cat siblings.