I would not recommend a greyhound. I used to foster them a few years back and although they are great indoor dogs/couch potatoes, they're not really very good outdoor dogs...as in for hiking and stuff. They have very thin skin which tends to rip in the bushes and briars and it's also difficult to teach them to come when you call. Especially if there's a squirrel half a mile away and they take off after it. Also as someone else mentioned, a lot of them are not trustworthy around cats, though some are fine.
My suggestion would be something like an Australian Shepherd. Very loyal, very easily trained, small enough for an apartment, not hyper but are active outdoors. Personality very much like a Golden Retriever or Lab but smaller. Just make sure you get the AKC variety not the working lines, those tend to be more hyper.
My suggestion would be something like an Australian Shepherd. Very loyal, very easily trained, small enough for an apartment, not hyper but are active outdoors. Personality very much like a Golden Retriever or Lab but smaller. Just make sure you get the AKC variety not the working lines, those tend to be more hyper.