The issue with using Bloodhounds for hunting game is that their noses are basically too good. You don't want to trail something that passed through a week ago. They certainly can distinguish between a fresh and an older trail, I can see the difference in my dog when we're close to the find, but if all there is is an old trail in the area anybody hunting animals doesn't particularly want to follow it. It's better to have a dog that will only follow a fresh trail in the case of hunting. Bloodhounds are also expensive to buy and feed, and more cumbersome to transport, than a more suitable breed.