I have Pokemon X and Houndour was found in Route 10. I'm sure by that point in the game you have at least seen Houndour via an encounter with Team Flare, so you can check the location on its Pokedex. Did it say "location unknown" or something like that? If it did, then it's a version exclusive, although I wonder what its Y counter part is.
Houndour is X exclusive, and Electrike is Y exclusive.
I can trade you a Houndour, if you like.