This is a specific conversation about Dog food allergies — identifying and fixing them — ask about yours and get one honest answer for your exact situation.
inparticular.ai
Switching between three grain-free foods and still seeing runny stools tells me grain probably isn't the culprit here — it's more likely a protein source your dog keeps reacting to, since most of those foods share common proteins like chicken. True food allergies are actually less common than intolerances, but the fix is the same: a proper elimination diet using a novel or hydrolysed protein your dog has never eaten before. To point you in the right direction, can you tell me — what proteins have been in those three foods you've tried, what exactly are the stools like (fully liquid or just soft and loose?), and have you spoken to a vet yet or are you troubleshooting this yourself so far?
She's two years old, a Border Collie. All three foods had chicken in them — I didn't really clock that until now. The stools are loose and unformed rather than fully liquid. No vet yet, just trying different foods. She's otherwise energetic and normal.
inparticular.ai
That's a really useful detail — chicken appearing in all three is a classic pattern. If she's reacting to chicken protein, switching between grain-free chicken foods won't change anything. The good news is she sounds otherwise healthy, so this looks like a dietary intolerance rather than something more serious. Before I suggest a specific food, one more question: has she eaten lamb, duck, fish, or venison at any point — even in treats — or has it genuinely been chicken-based food her whole life?
Honestly mostly chicken. She's had the odd treat with salmon in but nothing regular. I don't think she's had lamb or duck at all.
inparticular.ai
Lamb is your best bet then — it's a true novel protein for her, which is exactly what an elimination diet needs. My recommendation is Forthglade Complete Meal Grain Free with Lamb, which uses a single animal protein source, no chicken, no grains, and no common filler ingredients that muddy the picture. It's widely available on Amazon UK, reasonably priced, and the ingredient list is clean enough to use as a proper elimination trial. Give it a minimum of six to eight weeks with absolutely nothing else — no treats, no table scraps, no chews unless they're also lamb-only. If her stools firm up in that window, you've found your answer. If there's no improvement at all after eight weeks, that's when I'd say it's worth a vet visit to rule out something like inflammatory bowel disease or a parasitic issue.
That makes sense. What about treats during the trial? She's used to getting them for training and she's pretty treat-motivated.
inparticular.ai
Good question — treats will genuinely break the trial if they contain chicken or any other protein she might be reacting to. The simplest fix is to use a portion of her daily Forthglade as training rewards instead of a separate treat. Just measure out her daily amount in the morning and hold some back for training sessions. If you really want a separate treat, Natural & Delicious Pure Lamb Treats are a single-ingredient lamb option you can find on Amazon UK — nothing added. That keeps the trial clean and still lets you reward her properly.
Really helpful, thank you. I'll order the Forthglade lamb today and start properly.
inparticular.ai
Good plan. Keep a simple note on your phone of stool consistency every few days — it sounds tedious but it actually helps you spot the improvement point clearly rather than trying to remember. Most dogs with a straightforward protein intolerance show meaningful improvement within three to four weeks, with full firmness by six. If she's not improving at all by week eight, get a vet to check for giardia or IBD, both of which can look identical to a food intolerance. Good luck — Border Collies are generally robust dogs and this is very fixable.
