My dog likes peanut butter
How did you know your dog likes peanut butter?
He eats it whenever I give it to him
Peanut butter is a great treat for dogs! But be careful, some peanut butter isn't for dog consumption and it can get them sick, so be careful and check the labels first.
My dog likes peanut butter. There's no harm here.
If the ingredients are all dog safe, then there's no problem at all I and I hope your dog really enjoys it. Just be mindful that they still have separate diets than us and some things might not fare well with their digestion.