A federal judge has thrown out a lawsuit challenging an ordinance that bars suburban pet stores from obtaining dogs, cats or rabbits from large commercial breeders.U.S. District Judge Matthew Kennelly is allowing the plaintiffs a few days to fix problems in their suit and file an amended complaint. But in his written opinion, he suggested the challenge to Cook County’s “puppy mill” ordinance still won’t have much more than a dog’s chance.The preamble to the Companion Animal and Consumer …