To be honest though, I'm really not looking to change food unless it's an issue he's having with the protein in it, as I can just switch to another of this brand.
They both actually like this food, and they never had an issue with the junk brand that was also grain heavy. Their stools were perfectly fine, we weren't having anal gland issues, the only reason we switched off it at all was because the vet thought his skin issue could be a food allergy, but turns out it was bacterial from the beach.
I do like that this food is better quality than the junk brand though, so we stuck with it.
I'm simply looking for something to add to it to firm the stools.
Not a bulking agent, just a firming agent.