Indeed, so it appears it does now affect stats. Nothing I can do about that though unfortunately. :(

uninstalling the mod fixed it, loaded in and the dog just had cut damage to where the old maxes were, bandaged and he's healing back to 180 on all parts

In 1.0.9 - installed with an elder dog already - this causes the dog's max hp to drop with damage (like a skeleton would) - probably something in the code causing max to scale with size ratio?

Good thing.
Can not you do the same with all the other oversized animals?
Please?

I actually had forgotten to do the other breeds. So it would have done nothing. :P

They've been added now. They'll all be the same size at maximum age. (so obviously don't use if you want your giant doggies to become puppy sized)

They are puppy sized again! Cute little doggos, mod works as intended, and they do revert to normal size without the mod. Importing not necessary, they can exit the building just fine with the mod unchecked. Not sure how the mountain dog you can start the game with would behave with this mod as i dont have a file with him saved anywhere (it gets Much bigger than that dogs you can buy from farms)