Dr Christina Snow
The problem with grain free pet foods
Grain free diets are becoming a popular food to feed pets. Their selection is often based on a well-meaning belief that these diets are more natural, have less carbohydrates and are less likely to cause allergies. Unfortunately with the increase of feeding grain free diets there has been an increase in the incidence of serious heart disease, with a recent study revealing that feeding a grain free diet may lead to heart failure (Journal of Veterinary Cardiology 2019) in previously healthy dogs.
Carbohydrates themselves, are important source of energy in our dogs. They typically make up 30-70% of dry dog food, and also help to ensure there is adequate fibre for satiety and reduce tartar build up. Fibre can help with weight control, colon health, digestion, and controlling blood sugar levels.
Common carbohydrate sources will usually be listed in the first few ingredients on the bag of dog food and include: barley, oats, brown rice, whole wheat, whole corn, and potato (or sweet potato). But grain-free and low-carb do not go hand-in-hand. To replace grains, grain-free food often uses ingredients such as potatoes, apples, and peas. In fact, some grain-free pet foods contain carbohydrate levels similar to or even higher than dog food containing grains.
If you suspect your dog is suffering from a food allergy (often seen as itchy inflammed skin, hair loss, skin infections and scabs), grains in the diet are very unlikely to be the cause of the problem. While food allergies in pets are uncommon, accounting for 1% of skin disease or less than 10% of allergic skin disease in dogs, allergies to grains are even rarer. Because allergies are an immune system reaction against a normal protein, the small numbers of pets that do have allergies are most likely to be allergic to animal proteins. In dogs the commonest reported food allergens are beef, dairy and chicken and in cats are beef, dairy and fish.
As grains do contain protein, allergies to grains such as wheat can occur. However, reactions to other grains and carbohydrate sources, such as rice, corn, and potato are very uncommon. If a dog or cat has a diagnosed food allergy, treatment involves feeding either a hydrolysed diet or a food containing a single protein and carbohydrate source which they have not been previously exposed to. These are called novel protein and carbohydrate diets. Take care when choosing a food claiming to be hypoallergenic or novel. While they may only have one protein and carbohydrate source mentioned on the front of the pack, on closer examination of the ingredient list you may find several other sources of both.
At Glenelg Vet, we recommend feeding quality premium pet food, that is available from veterinary clinics and some pet food stores. In addition, it's important to choose a formulated food that caters for the life stage and breed size of your pet.