I have 3 cats and have fed them grain free blue buffalo dry food. I have heard a little info that all dry is not good for cats , especially males. What types of disorders are related to this type of feeding? I have tried ALOT of wet food over the past 21/2 months and they aren't going for it. One cat has a sensitive tummy and is very skinny ( I had him checked out at the vet and told he could use a little weight but that he was fine otherwise. He is 8yrs old. I am wondering if dry food could eventually cause harm?