Hydrolysed protein food for Cocker Spaniels

It sounds like your vet has already done the hard diagnostic work for you — a hydrolysed protein food is exactly the right call when a dog has a confirmed or strongly suspected food allergy. True food allergies in dogs are actually less common than intolerances, but when they do occur, hydrolysed protein diets are one of the most reliable fixes because the proteins are broken down so small the immune system doesn't recognise them as a threat. Before I point you to a specific product, can you tell me a bit more? What symptoms is your Cocker Spaniel showing — is it mainly skin and itching, digestive upset, or both — and has the vet given any steer on which protein source to avoid?

Itchy ears and paws plus recurring ear infections is a really classic presentation for a food-related allergy in Spaniels — Cocker Spaniels are actually more prone to it than most breeds. The good news is that description gives you a clear target. Since chicken and beef are suspected, you need a hydrolysed diet that avoids both entirely. My recommendation is Royal Canin Anallergenic. It uses hydrolysed soy protein and hydrolysed feathers as its protein sources — neither of which your dog will have been exposed to in any meaningful quantity — and the hydrolysis process brings the protein fragments down to a molecular weight low enough that it's considered one of the most hypoallergenic diets available commercially. It's also nutritionally complete, which matters because she'll need to stay on it exclusively for at least 8 weeks for a proper elimination trial.

Yes, I'm afraid 8 weeks is the minimum — and some vets prefer 12. The reason is that skin allergy symptoms can take weeks to fully resolve even after the trigger is removed, so a shorter trial can give you a false negative. You might see improvement at week 4 and think it's not working, when actually she just needs more time. And yes — the diet has to be completely strict. No treats, no table scraps, no flavoured chews, no dental sticks unless they're labelled hypoallergenic. Even a small amount of the offending protein can reset the clock. If you want to give her something during the trial, plain rice cakes or a small piece of the Royal Canin Anallergenic kibble as a treat works fine. The strictness is what makes the result meaningful.

Gradual is better, especially if she's had any digestive sensitivity alongside the skin issues. Over about 7 days, mix increasing amounts of the new food with her current food — roughly 25% new on days 1-2, 50% by days 3-4, 75% by days 5-6, then fully switched by day 7. Some owners going through an elimination trial worry about introducing the old food during the transition period, but in practice the amount is small enough that it won't significantly affect the result — and a sudden full switch can cause loose stools that make it harder to read her response. You should start counting your 8-week clock from the day she's fully on the new food. Royal Canin Anallergenic is available in dry kibble, which is what I'd suggest — the wet version exists but the dry is easier to portion and keeps better once opened.

Not necessarily, but it depends what you want to do next. If the symptoms clear up on the elimination diet, the classic next step is to reintroduce one protein at a time — say, add chicken back in for two weeks and see if symptoms return. That tells you exactly which protein is the culprit, which gives you much more flexibility long-term because you just need to avoid that specific ingredient rather than staying on an expensive hydrolysed diet indefinitely. That said, some owners find the hydrolysed food works so well they just stick with it permanently, which is also a perfectly valid choice. Either way, once you've confirmed the diet is working, it's worth going back to your vet to discuss the rechallenge plan — they'll want to know the outcome and can advise on whether her ear infections need any additional treatment while the diet takes effect.