Novel protein

A novel protein is a protein source the animal has almost certainly never eaten before, which is exactly what makes it useful in diagnosing food allergy. Because an allergic reaction depends on prior exposure and sensitisation, a protein the immune system has never encountered cannot, in principle, trigger an established food allergy, so feeding one allows an elimination trial to test whether signs settle. Classic choices include unusual meats such as venison, rabbit, kangaroo or horse, and increasingly insect protein, which is genuinely new to most pets. The catch is that novelty is relative to the individual's history: as exotic ingredients spread into mainstream foods and treats, yesterday's novel protein becomes today's commonplace one, which can undermine an elimination trial if the animal has been exposed unknowingly. This is the chief difference from the [hydrolysed protein](/glossary/hydrolysed-protein) approach, which sidesteps the exposure problem by breaking a protein down rather than relying on it being unfamiliar. Strictness matters: a true elimination trial means the novel protein and nothing else for several weeks, no treats, flavoured medication or table scraps, under veterinary guidance. On a label, novel-protein diets name a single, unusual protein and carbohydrate source. They sit at the heart of investigating adverse food reactions in dogs and cats. See the [Petipedia glossary](/glossary).

Petipedia · Editorial team

General documentary information. For an individual animal, a veterinarian's advice takes precedence over any online content.