Duck

Duck supplies complete protein and is fattier than chicken. It often appears in foods meant as alternatives for pets that react to more common meats, though there’s little research on how often it causes reactions itself.

A label can name duck on the front and still contain chicken fat or meal lower down. If your pet has a food allergy, read the whole list, not just the name on the front: the same animal can appear as a fat, a meal or a flavour. Ask your veterinarian.