I sure hope that Taz's weight loss isn't related to any serious health related issue. Have you ever tried mixing the wet food with some of the dry food? This way he'll also be eating more of the dry food and it won't be as hard for him to go back to eating only dry food again.

I feed both Storm and Sunny 2 feedings of wet and dry food mixed together and 2 more of only dry food. They seem to like it. Sunny's tummy can't tolerate only wet food because he eats it too fast so he'll then throw it up. I sure hope that Taz will gain the weight that he needs to and be able to maintain it. Good luck.