Which is 'better' depends on what it is you want from the animal. If you're looking for a low maintenance animal that doesn't require all that training and exercise dogs would need then a cat would be a good pick.Many are also affectionate towards their owners despite the stereotypes. Plus if you got indoor cats you dont have to let them outdoors for them to go toilet just use litter trays and scoop out any mess through the day to avoid a smell. With dogs no matter if it's raining, snowing, or hot it needs to go outside to go toilet. And in some cases need to be walked just for them to go toilet. Dogs are great if you enjoy a more 'Hands on' companion. One that needs more time and effort put into its training which youll be doing with it for the rest of its life. Theyre an animal that thrives on routine and stability from its owner. Theyre also bred and used for different things; Companion, Tracker, Herder, Hunter, Protector, Service/Therapy etc.