Yes, absolutely. Dogs can really get creative. I know of Alsatian / dachshund mixes. Not quite as extreme but still makes you wonder.

Some breed combinations cannot necessarily give birth even if pregnancy can start.

In fact also some pure breeds cannot give birth except by Cesarean section.

All I have to say is thank goodness that dogs and furniture are not interfertile.

Although if you have ever read the original Dune series... chairdogs.