Am sorry to report that Clucky's absolutely right - Optima dog food is killing dogs in China.
The food is contaminated with aflatoxin - the same stuff that killed a bunch of dogs in the US that ate contaminated Diamond brand dog food two years ago.
This is only affecting dogs in Mainland China, as the reason the aflatoxin formed was due to the dog food having been improperly stored in the southern city of Guangzhou (hot and humid climate) because of tightened shipping/importing regulations during the Olympics.
My dog was just diagnosed with this as well. Her liver is failing, and despite having her on all sorts of medications, her odds of survival are still quite grim. Once exposed, there's not a whole lot that can be done other than trying to support the liver as best as possible and hoping the dog is strong enough to pull through.
Even if the dog does survive the initial poisoning, it is likely to have chronic liver disease for the rest of its life, and has an excellent chance of developing liver cancer, as aflatoxin is a big time carcinogen.
I've posted more about this (and my pup's experience)
on my blog, so I'll not relay it all here - but if you are in China and feeding your dog Optima - definitely follow Clucky's advice and get your dog to a vet pronto.