A small amount of vegetables in cat food is fine as long as they are low on the ingredient list--as long as the carb count is low they're not going to hurt anything. I tend to stay away from anything with grains, even if the food is under 10% carbs, because Bandit's blood sugar tends to raise from it. For example, I can't feed him Friskie's flavors that contain rice at 6-7% carbs or his blood glucose elevates, but I can feed him Merrick's Grammy's Pot Pie or Turducken at 8-9% carbs because the potatoes that make it a bit higher in carbs don't effect his blood sugar like rice does. Also, it's been my experience that Bandit needed lower carbs when he was on insulin (less than 6%), but once his pancreas started working again he could handle the 8-9% carb foods just fine, as long as there was no grain.
But...every cat is different, and some handle carbs better than other. Staying under 7% is generally a good rule, because most everything with grain will be higher in carbs than that.
Personally, I feed Bandit the lower carb Merrick's 5 Star Entrees (Cowboy Cookout, Surf and Turf, etc.), which do contain some vegetables. He actually does way better on this food than he did on EVO 95% or Merrick's Before Grain because of higher protein/lower fat content. The high fat in the 95%/96% foods irritated his stomach/bowels a bit and it was very hard to maintain a healthy weight with him. Since I started feeding him the Merrick's, his coat has become insanely soft and shiny, his fat has turned to muscle, and he's easily maintaining a very healthy weight. So I'm a HUGE fan of that food now. I've tried many over the years and this was definitely the winner for Bandit.
