Explaining grain-free & hypoallergenic pet food
LAST month, I wrote about trends in the world of pet food, and since then, a few people have questioned me about two in particular: “grain-free” and “hypoallergenic”. Both of these terms are commonly seen on pet food packaging, and they deserve further discussion.
First, “grain free”. If you imagine dogs’ ancestors roaming as wild creatures, you would never see them tucking into rice or cereals. Surely they would just catch prey and eat it? Why, then, should we feed grain to out pet dogs? Isn’t this just something that is added by pet food manufacturers to bulk out their mass produced products?
I can understand this theory, but it’s completely wrong. We know from genetic studies that domestic dogs evolved the enzymes and digestive apparatus to eat and digest grain over five thousand years ago. This happened as dogs moved from being wild creatures to being human companions: there have always been grain-based leftovers from human communities. Grains form a significant part of our own diet, and it’s been traditional for thousands of years for us to pass on surplus to our canine friends. And they have thrived on this.
There are only two times when grains may cause problems for dogs.
First, I have seen farm collie puppies being fed nothing but porridge oats. This may have seemed economical and convenient for the farmer, but unfortunately, oats alone do not provide a balanced diet. The pups suffered serious ill health, with ulcers in the mouth, stunted growth and digestive upsets. The problem was not that the pups were eating oats; rather, it was the fact that they were eating nothing but oats. They were deficient in protein, vitamins, minerals and fats; key parts of a balanced diet.
The second time I have seen cereals causing problems has been when dogs have a genuine allergy to gluten, a glycoprotein that is found in many grains.
I have only seen this on a few occasions in a lifetime of being a vet. The most common cause is an inherited genetic abnormality seen in Irish Setters. Gluten-sensitive enteropathy (also known as celiac disease) is the human equivalent. The signs in dogs are digestive disturbances and poor growth. This condition is the only rationale that I can see for feeding a grain-free diet, and it is very rare indeed.
People sometimes claim that dogs don’t need carbohydrates. This is not true: carbohydrates form a normal part of a balanced diet, providing an energy source. Grain-free food often just replaces grain carbohydrate with vegetable carbohydrate. For example, maize (corn) may be replaced with potatoes, which contains just as much, if not more, carbohydrate. The term “grain” means seed from cereal plants (for example, barley, corn, millet, oats, rice, rye, sorghum, and wheat). Other plants may have seeds but are not considered grains, such as buckwheat, chia, flax, quinoa, peas and soy. So grain-free diets may contain these ingredients, some of which have only been used in pet food recently, so not as much is known about them compared to others that have been widely researched and used in the livestock and pet food industry for many years.
There is no scientific reason for dogs not to eat grains, and indeed, there have been some reports from the USA that some grain-free foods may even cause health issues, such as heart failure, either because of missing nutrients or because of extra ingredients in cereal-alternatives that may in some way interfere with cardiac health. Research is still underway on this, but my take-home message is “why use grain free food at all, when there is no evidence that grain does any harm?”
What about hypoallergenic pet food? It’s important to understand what this means. Allergies are more common in dogs than in the past ( just as in humans). And yes, a pet can be allergic to something in their diet. So the general idea is that hypoallergenic diets should contain fewer ingredients – less allergens – than standard diets.
Food allergy is very rare in pets. When it does happen, the allergy is caused by a protein ingredient in the food. To stop the allergy, you need to stop feeding that specific protein.
The typical scenario would be a dog with itchy skin disease that the vet thinks may be caused by an allergy to something in the diet. The vet would suggest putting the dog onto a trial diet with very few ingredients (e.g. mutton and rice). If the dog stops itching, then this confirms that the dog was allergic to something in the previous diet and it’s avoided in future. Other ingredients are gradually added to the mutton and rice, to work out precisely what was setting the allergy off. By a process of trial and error, the specific protein causing the allergy can often be tracked down, and avoided in future. Vets these days have special ultra-low allergen diets to make it easier to track down which protein is causing the problem.
So feeding a so-called hypoallergenic diet may, in theory, expose your dog to fewer allergens than standard diets, but this is more theory than necessarily something that is going to make any individual dog less likely to be itchy..
Choose your pet food carefully, and make sure that you understand the truth behind the label.