Shih Tzu sensitive stomach food in a multi-dog home

A Shih Tzu with a dairy sensitivity and a Labrador who'll hoover up anything in reach — that's a combination that makes feeding time genuinely tricky. Sensitive stomach issues in dogs usually fall into a few categories: food intolerance, ingredient sensitivity, or a gut that just needs a simpler diet. With a confirmed dairy reaction, you're already a step ahead in knowing what to avoid. To point you toward the right food, it helps to know: how old is your Shih Tzu and what symptoms triggered the dairy diagnosis — loose stools, vomiting, something else? And what are you currently feeding both dogs?

That's a clear cause-and-effect pattern, which is actually reassuring — it means her gut is otherwise probably fine, she just can't process dairy proteins. The issue with standard supermarket kibble is that many contain whey, milk derivatives, or cheese flavouring tucked into the ingredients list. Moving her to a food that's explicitly dairy-free and uses a single, clean protein source will settle things down quickly. Before I suggest something specific: is she currently at a healthy weight, and does she have any other known sensitivities, or is dairy the only thing you've pinpointed so far?

That cross-feeding concern is really the crux of it in a multi-dog home, and it's the right thing to think about. My recommendation is Forthglade Natural Lifestage Adult Grain Free wet food — the turkey or chicken varieties. It's completely dairy-free, uses a single named meat protein, has a short and readable ingredient list, and contains no grains, which removes another common irritant for sensitive dogs. Crucially, it's nutritionally balanced and entirely safe for a Labrador to eat, so the occasional stolen mouthful isn't a problem. For your Shih Tzu, the wet format also means you can portion it precisely, which makes cross-contamination with the Lab's bowl easier to manage. Feed her separately if you can — even just in a different room for ten minutes — and the combination of a clean food and controlled feeding should clear up the loose stools within a couple of weeks.

Even when the current food is causing problems, a gradual transition is still the better move — swapping abruptly can cause its own bout of loose stools just from the change itself, which makes it hard to know what's what. A 7-day transition works well: roughly 75% old food, 25% new for the first two days, then 50/50, then 25% old and 75% new, then full switch. If her stools are already quite loose, you can stretch that to 10 days to be cautious. Once she's fully on the Forthglade, you should see a clear improvement within two to three weeks.