I don’t know about that particular food, but when you switched foods did you mix it with the old food? I change foods over about a month by mixing about 1/10 of the new food into the old and increasing it after a few days or a week, and I mix it all ahead of time. I think this is longer than most people, it seems common to do it in a couple of weeks, but most Havanese do benefit from any gradual change. Mine has a sensitive stomach and going slow makes it obvious if it’s an adjustment period or the food is causing a problem. I usually start with a good portion of the old food and set some aside in case I need to add more of it at some point, or the food change doesn’t work out. When I mix up the rest, I do it all ahead of time, and I use food storage bags and increase the new food in each by small 1/10 increments. The first two weeks I go more days without increasing the food and only increase a little at a time, but if I start to run low on the old food as I’m mixing, I’ll jump to to larger amounts of the new food the last two weeks. By then it’s clear if there’s a problem, and if the change is going well, he’s adjusted pretty well.