That was a joke. Let me tell you the reason why it is funny...
Where do you find a dog with no legs?
Where do you find a dog with no legs? Right where you left it.
This is another legless dog joke. The humor in this joke cycle is dark humor - based on reminding people that legless dogs cannot move or stand up by themselves. It also involves (to work the best) a misunderstanding, because the listener will hopefully hear "Where can you go in order to discover a dog with no legs?" instead of "Where would you expect to find a dog with no legs after you left it somewhere?"