In a very real sense, they are the same species. They can mate and are such matings produce offspring. Those offspring, unlike a cross between an ass and a horse, are fertile as well. There are of course behavior and physiological differences, the later primarily related to the estrus cycle of the females, not to mention the wide variety of sizes, shapes, colors and behavioral characteristics we have forced on the poor dogs for our own reasons. None the less, they are the same. Coyotes too for that matter.
Yep, the gray wolf, red wolf, coyote, and dogs are all almost subspecies of one species, it seems. However I would like to preserve the gray wolf and red wolf. Coyotes and dogs need no help!