Actually, I just checked out Jackson's teeth again and they don't seem too bad. It's hard to tell in pictures but he does have some staining on the four canines (he also has an over-bite) but most of his teeth are all white still.
So a vet may say he doesn't even need one yet this year.
I'm glad his teeth are still pretty good because to be honest, I don't do as much as I should with them. I think if I started brushing every day (I do it about once a week now), they would REALLY look good. I do use Petzlife every time he gets a bath and also sprinkle some PlaqueOff onto his food.