One more thing. A bunch of wet foods have carrageenan, which is a thickener, and it is carcinogenic. It will tear up your cat's system and make her/him sick. Even really high end brands can have arageenan. There are lists on-line of the handful of brands that don't put this garbage into...
Here's what I've learned the hard way with my beloved kitties. Wet food is generally too dense-- even if it appears wet to us, it'll still lead to constipation after a while. I add a little bit of warm water to each dish of food (helps warm the food as well, after being in the refrigerator)...
I've been adding a little homemade chicken stock now to my little cat's canned food, but what made a HUGE difference was adding slippery elm to her food. I bought organic, powdered inner fiber, the same as what a human would consume, and I mix up maybe a teaspoon of powder with about 3...
I know this is an older post, but I am having the same problem with my cat. Canned food only for years, but now she is constipated. I've spent so many hours researching the problem, I thought I'd share one good starting place for folks wondering whether the poop looks normal...