1. You can walk through pets since an update pretty long ago. Just keep walking.
2. What about a pethouse outside?
Just like we need to have the crib for kids, we could need the pethouse(buyable from Marnie or such petshop) for some of these ideas, and building some stuff around the pethouse would keep them there... or they'd need to stay close automatically, and only 1 bunch(like 3 kittens/puppies?) per time, so you could keep all without getting more, or sell them and get more.
Or just be able to walk through them without touching first. So no hitbox at all.
No massive waves of pets, as that'd be too crazy for the game to handle.
You don't wanna take the whole ingame day to get out of your house, only to get in again to sleep, haha!
Wait, i think said pethouse would need to be inside, and the kittens/puppies not walk far (or having no hitbox), as they'd otherwise be out in the winter, too!
I'd love seeing the pet's hitbox go, so we can just walk without issues, and then having a few more wouldn't hurt(unless on very weak computer).