History Mystery

Let's play a game! It's called What the %$^& is My New Dog?

We're pretty sure he's part Border Collie. As for the rest, who knows?! I was sure he was mixed with pit, but after doing a little internet research I remembered I'm rarely right.

I found this picture of a Collie/Pit mix, which looks exactly like my dog.

But THEN, I found THIS picture of a Collie/Great Dane mix, which ALSO looks exactly like my dog.

Thoughts?