Casino drawing winnings are taxable. The question arises as to whether or not someone can deduct their gambling losses from a drawing winning? Guidance is provided here:
Drawings
It seems the crux of the matter is proving a direct relationship between the drawing and other gambling activity. If there is one, I'd be OK with an informed client taking the deduction. It would be helpful if Casinos took this into account, and structured their drawings in such a way as to require a minimal amount of gambling in order to enter the drawing.