Dogwise I've got a chihuahua, japanese spitz and australian kelpie, the kelpie is a herding dog so he tries to herd them by staring at them (or he tried to now he's just accepted that they only move if you nudge them and he's not allowed to do that) but I'd recommend a "sällskapshund" which is the grouping of companion dogs, I'm not sure what they're called in english and if none of those breeds suit you I'd just avoid hunting dogs and herding dogs you have to train them how to treat the dog. However almost any dog breed can work with piggies, especially if they grow up with them and you just make it clear from the start that piggies are not to be touched!