i agree with carillon.
what i'd do for that silver dollar is to treat the tank daily with liquid vitamins (like the afore mentioned VitaChem from
http://www.drsfostersmith.com/) to encourage fin regrowth and keep the water extra clean. That's worked wonders with our Bettas and in a month totally regrew a female bettas severely damaged anal fin, pectoral fin and scale loss from an apparent attack.
Then if it looked ANY worse, i'd start using the Rid Fungus. I'd also treat the tapwater with NovAqua+ while you're working on getting the fins to regrow (or something like StressCoat).
There's no real need for rid-ich and they have another product called ich-attack that we keep in stock in case of ich outbreaks. like the rid fungus, it's 100% organic and safe for all fish.
Best of luck with your little silver dollar.