Pet careers were introduced with The Sims 2: Pets, and carried over to The Sims 3: Pets for console. These careers are specially employed by pets only.
The Sims 2: Pets[]
Sims can find jobs for their pets by reading the newspaper or looking on the computer. Pets can get promotions in a career by learning the required commands. Each promotion unlocks a fur color or collar to use in-game. Kittens and puppies cannot get jobs, and elder pets can only continue the career they have held since adult, and cannot find another job. Once an adult pet becomes an elder, the Sim can let them retire. If pets are in bad mood, they will not go to work.
Cats are paid more than dogs in all three of the pet careers. According to the Prima official game guide, it is because cats learn behaviors and commands slower than dogs, making them worth more than dogs. This is also true when selling a cat and a dog with the same learned behaviors and commands.
The Sims 3: Pets (console)[]
Pet careers make a return in The Sims 3: Pets for console. Pets can become employed by traveling directly to the rabbit hole. There are five different careers, each with the same pay rates and working hours. These jobs are similar to Sim part-time careers, as they feature shorter hours and only three career levels instead of the usual ten. Some careers are exclusive to either cats or dogs.