Grain free, hypoallergenic pet diets are becoming increasingly popular. Dr Eloise Bright discusses whether cats and dogs are allergic to grain, what causes food allergies, and whether you should buy your pet a grain free food.
The way our own bodies digest food is very different from cats and dogs.
Our pets’ stomachs are designed to eat some pretty disgusting things – like possum poo!
Dogs and cats have a very short transit time from eating to evacuation (less than 24 hours and as short as 6 hours), while for humans this can be up to 5 days, allowing for the digestion of more complex materials. That means dogs and cats lack the ability to process grains as efficiently as humans, so they need these in a form they can manage.
Cats are pure carnivores so need a high protein diet from animal sources.
Dogs are technically omnivores, and over time have developed the ability to process starch and foods that their wolf ancestor could not.
Are cats and dogs allergic to grains?
There are lots of different types of grains. Some include gluten, such as barley, rye, wheat and oats. Others are gluten free, like corn, sorghum and quinoa.
There is currently no definitive evidence to suggest that grain causes allergies in dogs or cats. Some pets may develop skin allergies due to corn, but the most common food allergies in pets are to beef, dairy, chicken and lamb, rather than grains.
How do I know if my pet has a food allergy?
Food allergies may cause diarrhoea, vomiting or weight loss, but also often show up in the skin. So if your dog licks his feet, gets frequent ear infections or an itchy bottom, the culprit could be a food protein like beef. Cats often develop itching around the head with their food allergies.
The only way to diagnose a food allergy is by doing a food trial. We recommend chatting to your vet about how to do this properly so you don’t waste time and money on a food that won’t help.
You will need to feed a novel (or new) protein (like venison, lamb or kangaroo) with a carbohydrate source like sweet potato. Or you could use a diet designed for food allergies like Royal Canin Hypoallergenic or Hills Science Diet Z/D.
So should I try grain free?
Certainly there is no harm in feeding your pet a grain free diet. However more importantly, you should be feeding your pet a good quality, well-known brand that you know has excellent safety records. So avoid those cheap supermarket foods and buy as good a quality as you can afford. But consult with your vet if you have any concerns with your pet’s digestive system or skin so we can help you get to the bottom of the problem.