Don't think there is no money in the dishlickers, a very good friend had a dog called undermine,He made enough money on the dog, Prize money but mainly punting money to put a hefty deposit on a house.
I'll check with him the costs involved in buying and maintaining a dog and post back.
The main problem as I can see, it's like owning a racehorse, you get a real good one once in a lifetime if you are lucky.