Lagotto Romagnolo food allergy after switching brands

Symptoms appearing within days of switching food is a really useful clue — it points strongly to something in the new food rather than a long-developing sensitivity. True food allergies in dogs are actually less common than intolerances, and both can flare up when a new ingredient enters the picture. The most reliable way to get to the bottom of it is an elimination diet using a novel or hydrolysed protein. Before I point you in the right direction, can you tell me a bit more: what symptoms is your Lagotto showing, do you know the main protein sources in the Italian brand you switched to, and have you had a chance to speak to a vet yet?

Itchy skin combined with loose stools within a week of switching is a classic picture — those are the two most common signs of a food intolerance, and beef is actually one of the more frequent culprits in dogs. The good news is that your Lagotto hasn't been on the new food long, so you haven't had months of exposure to unpick. What I'd suggest is moving him to a single novel protein he's never had before — something with no beef, no lamb, and ideally no common fillers like wheat or soy. Has he eaten chicken before, or would something like duck or salmon be genuinely new to him?

Perfect — that makes salmon or duck a solid starting point for an elimination trial. For a 3-year-old Lagotto, I'd go with Canagan Atlantic Salmon Grain Free dry food. It's a single named protein source, grain free, no beef or lamb, and the ingredient quality is genuinely high — around 35% salmon with sweet potato as the carbohydrate base. Lagotti tend to do well on fish-based foods, and the grain-free formulation removes another common irritant. Run it as the only food for 8–10 weeks with no treats, chews, or toppers that contain other proteins — that's the only way to get a clean result. If the scratching and loose stools clear up, you have your answer. If they don't improve at all after 4–5 weeks, that's when I'd push for a vet referral to rule out environmental allergies or something else. The product is Canagan Atlantic Salmon for Dogs and it's readily available on Amazon UK.

Good question, and it's a bit of a judgment call. Normally a gradual 7-day transition is the right approach, but since his gut is already unsettled and you want a clean break from the suspected trigger, switching more quickly — over 3 to 4 days rather than 7 — is actually reasonable here. Start with 75% new food from day one rather than the usual 25%, and keep an eye on his stools. If things get worse rather than better in the first few days, that's useful information in itself and worth mentioning to a vet. But most dogs with a food intolerance start to improve fairly quickly once the offending ingredient is removed.

That sounds like a solid plan. Keep a simple diary — just jot down stool consistency and scratching frequency every couple of days. It takes the guesswork out of it and gives you something concrete to show a vet if you need to. Most dogs with a straightforward food intolerance show meaningful improvement within 3–4 weeks. Good luck with him.