Do you mean 'dietician' or 'nutritionist'?
A groomer would make more money grooming show dogs... following the circuit around and actually grooming before the shows.
Fitness trainer... like a personal trainer? Or maybe consider massage therapy (where people go after seeing their personal trainer).
Best bet... discuss your interests with a college admissions advisor (maybe available at your HS). They can test you to see what profession you would be best at.
http://www.google.com/search?q=dog+g...rchBox&ie=&oe=