Dry food & male cats

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?

The best info on dry food is at catinfo.org. It's written by a DVM, and she has written a lot on why dry food is not good for cats. Basically dry food can be particularly concerning for male cats because dry food can lead to chronic dehydration which leads to concentrated urine which can lead to urinary tract problems. Male cats are more prone to blockages which can be life threatening.

Dry food can also contribute to obesity which can lead to diabetes and kidney problems.

There are also tips on catinfo.org about transitioning cats to wet food.

Trust me on this-any urinary issues with a male cat is an absolute nightmare. I fed Kairi dry and wet, but most days, he will not eat the wet food. He loves water, he plays in it, drinks it, splashes it, and soaks his dry food in it. I figured he was taking in enough water. I was wrong. He has had 3 urinary problems, and 2 surgeries and he's not even 2 yet. 

He came home from having a Urethrostomy on friday, and he's eating Royal Canin SO canned food. he loves it, and it will be his diet for the rest of his life. If a male cat becomes dehydrated in any way, and develops crystals in his bladder...they will block him eventually. 

I'm not sure of other issues resulting from feeding only dry, but for me, a lesson learned. No dry food again EVER for male cats in my home. 

Adding canned food would absolutely be very important to your cat's urinary health. Here is a good article on tips to help you make the transition, if that is what you want. I would personally suggest it. So very important because of the high moisture content of wet foods. http://catinfo.org/#Transitioning_Dry_Food_Addicts_to_Canned_Food_

Here's another thread recently started with a very similar question:

http://www.thecatsite.com/t/257115/how-well-do-cats-survive-on-dry-food#post_3334272

I really do think some cats are predisposed to getting certain illnesses , but I also think that the food they eat can help intervene.