My cat, who is 18 years old, has recently developed quite the sensitive stomach. He has an upset tummy nearly every day, & I think it’s probably his food. I’m trying to find one that fits all 3 qualifications, but I can’t seem to find a cat food for senior and sensitive stomach. He’s been eating Iams indoor senior formula, and I’m considering switching him to Nutro Senior, because it says it’s easy to digest. Has anyone else used Nutro, or have any suggestions for a good brand of senior sensitive stomach food?

More specifically, whats in dog treats thats so different from regular dog food, and makes dogs freak over their treats? Why isnt this just added to regular dog food to make it more appealing to dogs, not that it really matters?