Can't assign dog

[Rowan]

I'm having troubles with my dogs. I have a pet house on both sides of my farm, but if I try to assign them to a barn or coop with the book, the only option I get is to place the dog in my house or the other pet house? A barn or coop option isn't given.
Could the game not work properly or what am I doing wrong?
My barns and coops and pet houses are surrounded by fences. One puppy has 5 hearts but none of them herd a single animal

[Night Owl]

It seems like you're "Moving" the dog, not actually assigning them to a task. I believe it's the X button that allows you to bring up that menu. Then you get the choice of barn or coop. Now, if you've never had a dog do the chores, they will slack off. They need to be trained in order for them to consistently take animals in and out of the barn. You'll need an animal whistle to make sure they do their chores. The book inside the Pet Barn will tell you if/when the dogs are slacking off.

There's one thing I'm unsure of, and that's if the barn the dog is in has to be on the same side as the barn/coop you want to assign it to.

[Shan O 123]

^Yes, I believe they need to be on the same side. Otherwise it won't work

[Arcy]

Yes, the Pet House containing the dog does have to be on the same farm screen as the Barn/Coop with animals in it for herding to work.

[Rowan]

Thanks for this answer!! Finally I could assign my dogs. The x button was needed, not the a button.