Pet sitter, dog walker, kennel worker. Even dog groomers need to be trained and generally licensed. An assistant at a vet clinic (makes appointments, cleans cages, and often starts the exam by weighing the pet etc). A dog trainer at Petsmart is not a full time job - it's an employee who's had a couple training classes. Jobs working with animals that pay well are the same as jobs in other fields - you need some sort of training and often certification to make a living out of it. Most jobs that you do on your own require some sort of insurance and bonding, too - if you are walking dogs and the dog gets away and attacks another dog for example, you need insurance to pay for the bills and lawsuits. Even working as a pooper scooper generally means you need to be insured and bonded.