The section of companion proficiencies says, "It’s trained in its unarmed attacks, unarmored defense, barding, all saving throws, Perception, Acrobatics, and Athletics. Animal companions can’t use abilities that require greater Intelligence, such as Coerce or Decipher Writing, even if trained in the appropriate skill, unless they have a specialization that allows it." Since actions associated with some skills are called out as not being possible, even if the companion is trained in the related skill, that implies to me that actions associated with trained skills that don't require greater intelligence are completely kosher.