A hydrolysed protein has been broken down into fragments small enough that a dog's immune system is less likely to recognise and react to it, which is a different mechanism from simply choosing a less common protein like duck or venison.

VetCare Hypoallergenic Hydrolysed Chicken with Sweet Potato leads with hydrolysed fresh chicken (26%), alongside sweet potato, potato and pumpkin rather than grain. Arden Grange state the dry recipe's protein at 26% and fat at 15%, with algae added for DHA.

• Available as a dry food (two bag sizes) and a wet tray
• Hydrolysed fresh chicken (26%) — dry recipe
• Protein 26%, fat content 15%, crude fibre 3% — dry recipe
• Contains algae for DHA
• Not suitable for puppies, pregnant or lactating bitches

On the wet tray. The figures above describe the dry bags. Arden Grange also sell this range as a wet tray for the same purpose, but the specific composition and analysis of that tray is not the fact card we have used to write this page — check the tray's own label before feeding it.

Who it's for: a dog with a diagnosed or suspected food intolerance or allergy, being fed this on a vet's guidance — not a dog simply switched to it on the assumption that "hypoallergenic" rules out every possible reaction.