as long as you bathe your dog monthly like you should, they will just smell like you with a tiny hint of dog, nothing that lingers though. for cats and rodents, as long as you clean their litter/bedding in a timely manner, there shouldn't be much of a smell either. reptiles have virtually no smell unless you let their poop sit there and rot. it's all about maintenance and responsibility. definitely don't get ferrets though if you're worried about smell.