I don't. I've found that if Jax won't eat it then the chances there is something wrong with it is pretty high. There was a dog food she refused to eat, the Boxer ate it for her. I woke up to pools of blood and diarhea all over the kitchen from the Boxers and Jax was lethargic. Threw the food out, all recovered. That was just after all those dogs and cats died from poisoned food. So I trust her nose. If she won't eat it, it gets tossed.