If the doses you've been giving aren't making him vomit, you're probably fine! It's my impression (that's all it is since I clearly don't have data) that most cats do okay starting with a half- or full dose. I made a big and very stupid mistake with Edwina by giving her too big a dose on a day that she'd barfed. I don't rightly remember if I gave her a half- or full dose but whatever it was made her barf again. I waited a week or two (this was when she wasn't doing well during hot, humid, loud weather) and then started over again with, literally, a pinch. By the time she got to a half-dose, we could easily see results: she was obviously more comfortable an hour or two after the FGS. I went faster with her sister, who's never been much of a barfer, though she gets constipated, something that Gut Soothe seems to have eased a lot.
The food part is much harder to deal with, isn't it?! We feed lots of homemade (cooked) food, which works very well for Edwina because it's so simple. For canned foods, there's Fancy Feast turkey pate, Tiny Tiger turkey pate, Rawz pates (duck, chicken, turkey), and Nulo chicken/duck mousse. There's also occasional Mouser, though the cats aren't thrilled with it. Our other cat has a chip feeder with Dr. Elsey's chicken dry food (very, very low carbs, the only dry food I'd feed) and a little bit of Grandma Lucy's Moxie dehydrated food that works really well for her as a topper or mixer. Ireland also gets small meals of certain "Perfect Portions" pates, which I feed her somewhat grudgingly because they have tapioca starch (albeit not very much) in them.
We have a big list of forbidden ingredients, some of which are known irritants to one or both cats: agar-agar (both barf!), potato, and green-lipped mussels. There's also a "strong suspects" list that I avoid for both cats, though I'm not absolutely certain these ingredients cause problems in either cat: carrageenan, xanthan gum, maltodextrin, and fish are among them. I also avoid tapioca for Edwina. I try to avoid anything chemically or unnecessary for Edwina, though some of the cats' foods have guar gum, which seems to be a "least bad" type of thing. This is what works (at least today!) for our cats but yours may have totally different needs and preferences. It helps me a lot to keep a journal of "incidents" that includes symptoms, last meal fed, time, and other factors, including the weather and other stressors. I've learned a lot about stress and cats in recent months. I've also learned to look up just about any chemical -- maltodextrin was my "aha" moment -- that's in a new food or treat that appears to be causing gut issues for Edwina. There are often clinical trials in hoomans that mention digestive issues. I'd rather err on the side of caution and eliminate something from the diet than put or keep it in the food and deal with consequences later. I learned my lesson with agar-agar!
Anyway, fingers crossed that the Gut Soothe will help Blacky!
