As I understand it, that "reveal" was undone a long time ago. John Byrne wrote a 1983 story where Gorgon and Karnak told the Thing that Lockjaw was an Inhuman who turned into a dog, but in 1991, Peter David revealed that they'd just been playing a practical joke on Ben. After all, given that everyone treats Lockjaw like a pet animal, it would be way too creepy and disturbing if he were actually human. There are some continuity and logic problems with PAD's retcon, but as far as I know, Lockjaw's been consistently treated as a dog for the past quarter-century. And screen adaptations generally tend to stay consistent with the current versions of characters.