We have previously determined that an awakened creature or a familiar can attune to magic items, but one of those is a sapient creature, and the other "always obeys your commands". A paladin's steed (per the Find Steed spell) is also 'unusually intelligent' and falls within the score range for sapient creatures.
But what about a regular old animal? If my ranger has a wolf companion, can he make that wolf attune to, say, an Amulet of Health? According to the Beast Master archetype, a companion animal "obeys your commands as best it can". Is spending an hour 'focused only on the item' (as required for attunement) something a beast can manage? Or what if it's not an Animal Companion, but just a riding horse, a pet dog, a trained magpie?
I know, probably this is going to be down to the DM to determine, but is there any guidance we can use to help decide whether my cat can attune to an item, and whether rubbing it with catnip would help?