Some vets do recommend mixing wet and dry, just make sure to:

• Read the label: Check the ingredient list for words you can actually pronounce and make sure it has no excessive fillers.
• Check for "BPA-free" or "BPA-non-intent": Look for brands that are processed without BPA.

I am a firm believer in reading labels on everything. The rule of thumb is if you can't pronounce it, you shouldn't put it in your mouth. The same goes for our fur babies.