How to prevent fatty cysts on my dog?

Well my dog is almost 10 years old (he's a golden retriever.) and he has lots of what the vet diagnosed as fatty cysts. I'm in the process of switching him from iams to wellness core reduced fat. The fatty cysts i swear there's a new one every week. How do i prevent them? Or make them smaller? I know they're fatty cysts and not cancer (the vet tested for it.) So if you have any suggestions it would really help.

I assume you mean lipomas? (a benign fat lump). Technically speaking --- they are a cancer, but benign (i.e. don't cause a problem). Cancer just means an abnormal replication of cells. (it doesn't, as many people seem to believe, mean a poor prognosis, or that you have to do anything about them). Your vet likely just didn't want to get in to the 'technical details' with you, so has decided to call them 'fatty cysts'. (because it probably gives a more accurate impression of what you're dealing with, even though its not the most accurate/precise term to use). Some breeds, and some dogs, just seem to get them. Don't worry about them, unless they start to grow quickly, or interfere with things. I've yet to see any reasonable 'preventative measures' you can take that will reduce the incidence of them.