Pathfinder Animal Companion Item Slots

We've got a druid and a ranger that both have wolves for companions. As our group has no traditional tank fighter we tend to use them quite a lot in combat. I'm about to take up a collection to get them some equipment.
My question is: what exactly can they use? I'd like to get them some form of light weight armor/barding that won't slow them down too much (leather most likely - especially for the druid's wolf). My co-DM has mentioned magic collars, but do wolves (or other quadrapeds for that matter) have any other 'magic item slots'?
Thanks.
CompanionItemPathfinder

Pathfinder Society Animal Companion Item Slots

Pathfinder animal companion magic item slots

Pathfinder Animal Companion Magic Item Slots

Explosino Casino is a multi-software, multi-platform casino providing Canadian players access to Pathfinder Society Animal Companion Item Slots thousands of top gaming from the best software in the business. Animal companions can assign skill ranks to any skill listed below. If an animal companion increases its Intelligence to 10 or higher, it gains bonus skill ranks as normal. Animal companions with an Intelligence of 3 or higher can purchase ranks in any skill. An animal companion cannot have more ranks in a skill than it has Hit Dice. The Pathfinder rules only explicitly state the slots available for humanoid creatures. However, there are two possible leads on an answer - this Paizo thread quotes an old 3.5 'Rules of the Game' article allows up to 12 slots, but the ruling in Living Greyhawk games was only slotless, animal specific, barding, and amulet (collar). Animal Magic Item Slots This product is compliant with the Open Game License (OGL) and is suitable for use with the Pathfinder Roleplaying Game or the 3.5 edition of the world’s oldest fantasy roleplaying game.