Dog food for Leonberger with oat sensitivity

A Leonberger with a confirmed oat sensitivity in a home where the other dogs are already on oat-containing sensitive stomach food — that's a genuinely tricky management situation, and it's worth getting the food choice right so you're not constantly firefighting. Sensitive stomach issues in dogs usually fall into a few categories: food intolerance, ingredient sensitivity, or a gut that simply needs a simpler diet. Identifying which applies is the key to finding the right food. To point you in the right direction — what symptoms does your Leonberger show when they've been exposed to oats or an oat-containing food, and have you had any formal diagnosis or is this based on a pattern you've noticed yourself?

That's a consistent enough pattern to be meaningful — loose stools and gas within 12 hours of eating oat-containing food, repeatedly, is a strong signal. At 65kg he's a big dog, so even a modest amount of the other dogs' food is a real dose. Before I suggest a food for him specifically, it helps to know what he's currently eating day-to-day. Is he on a sensitive stomach food of his own, or a general adult food, and is it grain-free already?

That makes sense — you've been in a holding pattern waiting for the right answer rather than guessing. The good news is the solution for him is reasonably straightforward: you want a grain-free, single or limited protein kibble with no oats and no cereals at all, so that even if cross-contamination happens occasionally, the base diet isn't loading his gut further. For a Leonberger his size you also want something with a good protein level and no unnecessary fillers. The food I'd recommend for him is Canagan Grain Free Chicken for Dogs — the original red bag, Country Game or Free-Run Chicken varieties both work. It's genuinely grain-free with no oats, wheat, or maize, uses named meat as the first ingredient, and has a clean ingredient list that suits sensitive systems well. It's available in large bags on Amazon UK which makes sense at his size. The key discipline on your end is feeding separately — even a few minutes in different rooms — so he can't access the Royal Canin. That's the management side no food can fix on its own.

Good instinct to ask. Canagan isn't formulated as a breed-specific large breed food, so it doesn't have elevated glucosamine or chondroitin levels the way some large breed foods do. If joint support is a concern for a 5-year-old Leonberger — and it's reasonable to think ahead on that — you have two options: add a separate joint supplement like YuMove, which is widely available and well-regarded, or consider Canagan Large Breed formula specifically, which is the same clean grain-free profile but with adjusted calcium-phosphorus ratios and added joint support for larger dogs. Either route keeps the oat-free diet intact. I'd lean toward the Large Breed version to keep things simple in one bowl.

You're all set. Canagan Large Breed grain-free, fed separately from the other dogs' Royal Canin, should settle his stomach and protect his joints going forward. Give it four to six weeks on the new food before judging — the first week or two can involve a transition period, so introduce it gradually by mixing with his current kibble over about seven days. If the loose stools persist beyond that once he's fully transitioned and you're confident he's not getting into the other food, it's worth revisiting with a vet to rule out anything else. Good luck with him.