M.I.
If it's just fleas then you dont need a vet, you need to purchase either frontline or advantage. You can find it either at a vet's or at petland or petco. I am not discouraging you from taking your cat to the vet if it's got other issues or needs a checkup however if it's feas than save yourself the money. I foster all kinds of critters and this stuff works within hours of applying to the back of the animal, it's very easy. Good luck.