Dog food allergy relapse in Welsh Springer Spaniel

That pattern — symptoms clearing on a hydrolysed diet and then returning after six to eight weeks — is actually a recognised problem, and it usually means one of two things: either the hydrolysed protein wasn't broken down small enough to avoid triggering a response, or there's a second allergen in the food (often a carbohydrate like wheat or even pea) that was always there but took time to accumulate. True food allergies are less common than intolerances, but either way the elimination approach is still the right one — you just need to change the variables. Can you tell me which hydrolysed food you were using, and what symptoms came back — skin, gut, ears, paws? That'll help me point you somewhere more useful.

That's really helpful. Royal Canin Anallergenic uses hydrolysed soy as its protein source, and soy reactions — even to hydrolysed versions — do occur in some dogs, particularly ones with a pattern of skin and ear involvement like your boy. The fact that it worked initially and then declined strongly suggests his immune system has now mounted a response to that specific protein. What you need now is a true novel protein elimination diet — something completely different in protein and carbohydrate from anything he's eaten before. Has he had duck, venison, or fish-based foods at any point in his life, including treats?

Venison it is, then. Given he's already been exposed to duck and salmon, venison is your cleanest novel protein option. I'd recommend Canagan Grain Free Venison for Dogs — it's a single-source novel protein food, grain-free, and importantly has a very short, clean ingredient list with no pea protein or potato starch, which are hidden culprits in a lot of elimination diets. It's available on Amazon UK in both dry and wet formats. For a proper elimination trial you need a strict eight to twelve weeks on this food alone — no treats, no toppers, no chews unless they're also venison-only. If you see improvement by week four, that's a strong sign you've found the culprit. Would you like advice on managing the transition, or on what to do if symptoms don't improve after four weeks?

With a sensitive gut, go slower than the packet suggests. I'd do ten days rather than the usual seven: days one to three, 80% old food and 20% new; days four to six, 60/40; days seven to eight, 40/60; days nine to ten, 20/80; then fully switched by day eleven. If you see loose stools at any point, hold that ratio for an extra two days before moving on — don't go back unless it's severe. One more thing worth flagging: during the elimination trial, his ear cleaning routine matters too. Yeast can take hold in already-inflamed ears independently of food, so if the ears don't clear up within three to four weeks on the new food, it's worth a vet check specifically for secondary yeast infection rather than assuming the diet isn't working.

Good luck with him — Welsh Springers are tenacious scratchers when something's bothering them, so getting to the bottom of it will make a real difference to his quality of life. Stick rigidly to the elimination trial, keep a simple symptom diary so you can see week-on-week progress, and if things haven't shifted at all by week six, it's worth going back to your vet to rule out environmental allergies running alongside the food issue. Hope he's more comfortable very soon.