Need to know
- Different animals, including cats and dogs, have different nutritional needs, so do your research before making major changes to their diets
- The greatest risk to most pets' health is obesity, either because they're given the wrong food, or because they eat too much in general
- There's no evidence that so-called superfoods, such as kale, or 'exotic' meat, such as kangaroo, give your pets any extra health benefits
Premium pet foods make claims about containing high-quality, often human-grade, ingredients; being grain-free; having a high meat content; and including human superfoods.
They include pet store foods such as Black Hawk, Ivory Coat, Ziwi Peak and Taste of the Wild; vet-supplied foods such as Advance, Hills and Royal Canin; and also some supermarket foods (especially grain free) and foods that simply call themselves 'premium'.
While they all have different claims for 'premiumness', one thing they all have in common is their higher cost. But are they any better for your pet? We take you through some of the features of premium pet foods and their claims.
Regular dry pet food contains grains such as wheat, barley, corn and rice, and they're sometimes used in wet food to provide fibre. Mirroring human dietary trends, grain-free products for pets are becoming increasingly popular.
But just because a dry food is grain free doesn't mean it's carbohydrate free. Kibble requires some sort of starch to hold the meat and fat together, so vegetables such as potato, sweet potato and cassava, or legumes such as peas and lentils, are used instead. Legumes are high in fibre and can provide a useful source of protein in addition to carbohydrate. But starchy vegetables tend to be lower in fibre and other nutrients, and are more expensive than grains.
So should your pet go grain-free?
The anti-grain brigade is quick to argue that dogs and cats are carnivores – they hunt for meat, not wheat. Some are willing to concede that while dogs are omnivores – they can eat meat, grains, vegetables, fruits, discarded pizza crusts, kids' birthday cakes, including candles … pretty much anything really – cats are 'obligate carnivores' that can't digest grains and have to eat meat.
The anti-grainers counter that dogs are descended from carnivorous wolves and share 99.8% of their DNA, and therefore must be fed as carnivores. But the small number of genes in which wolves and dogs differ include a group related to the digestion of starch – and these genetic adaptations formed an important step in the early domestication of the dog. Grains are relatively cheap, and they're a source of protein, vitamins, minerals and fibre, so can play a valuable role in the diet of a dog.
Cats are a different story. A small study that let cats choose from foods with varying levels of carbohydrate, protein and fat found the ideal balance was 52% of energy from protein, 36% from fat and only 13% from carbohydrate – a similar balance to eating a rat! But in most dry foods, at least 30% of energy is supplied by carbohydrate, and only 30–40% from protein. Wet food is usually lower in carbohydrate, and may consist of just meat products, gelling agent and added nutrients.
So the question for cats is more about whether they should be eating large amounts of carbohydrate, rather than if they should eat grains specifically.
Risk of diabetes?
One concern is that a high carbohydrate diet may increase the risk of diabetes. Some studies have found this not to be the case, but a recent (2017) large Swedish study found cats with type 2 diabetes were more likely to have been fed a mostly dry diet.
That said, it's not clear whether it's because of the carbohydrate in dry food, or some other factor. Other researchers, for example, found that adding water to dry food made cats more active and eat less, and we know that inactivity and overweight are associated with diabetes.
There's no good evidence that dogs and cats on the whole do better on a grain-free diet
Limited research means there's no good evidence that dogs and cats on the whole do better on a grain-free diet, and no evidence a diet with grains does harm on the whole. In the many decades since the advent of prepared pet foods that contain grains, pets have been living long and healthy lives. By the same token, grain-free foods can be healthy, as long as they're from a reputable company.
From a sustainability perspective, plant foods are more environmentally friendly than meat products. But there will be some dogs that benefit from a reduced grain or reduced carbohydrate diet – skin problems and gastrointestinal upsets may be solved with a different diet.
In general, the far greater risk to pet health is obesity, which can come from eating too much of anything.
One of the greatest risks to pet health, in both cats and dogs, is eating too much of anything.
Living a gluten-free lifestyle? Well now your pet can too, with a variety of dog and cat foods claiming to be gluten free. As with humans, there's no evidence gluten is harmful to most animals – the main exception seems to be some Irish setters, which are susceptible to coeliac disease. If you suspect a genuine intolerance, see your vet about undertaking a proper food intolerance test for your pet.
There's limited data on the incidence of food allergies in dogs and cats, but they're uncommon in dogs and rare in cats. Symptoms are mainly skin-related (itching, redness, sores, hair loss) and gastrointestinal (vomiting, diarrhoea). Studies report the most common allergens in dogs are beef, dairy, chicken and wheat. For cats it's beef, dairy, fish and lamb. The only way to confirm an allergy is to put your pet on an elimination diet, supervised by a vet, and then reintroduce suspect foods to test for reaction.
The only way to confirm an allergy is to put your pet on an elimination diet, supervised by a vet
Meats are the main allergens, but it can be difficult to find food from single animal protein sources – a commercial food labelled 'lamb dinner' could also contain chicken, beef, pork and other meats. Checking the label carefully is important.
However, a 2015 UK study of animal DNA in pet food found animal species that weren't listed on the label, and a 2013 Italian study discovered unlabelled animal species even in special hypoallergenic diets.
An allergy – but which allergy?
When a product states it's 'hypoallergenic', it's important to check what allergy is assumed – and therefore what's absent from the product. For example, the range of Ivory Coat Natural Health Hypoallergenic products include potentially allergenic meats such as chicken and fish, so if your pet is allergic to chicken or fish, these products won't be hypoallergenic for them – but other varieties may be.
The Royal Canin Hypoallergenic food, on the other hand, contains hydrolysed proteins specifically designed for vet-supervised allergy diets.
Some premium pet foods claim to contain 'human-grade' ingredients, but will your pet really benefit from them anyway?
Some products claim to have 'human-grade' ingredients, although technically once a food has left the human food supply chain, it's no longer human grade. It's usually meant to imply the ingredients are good enough for human consumption, such as meat in the form of muscle meat, rather than byproducts, as well as various plant products and fats such as fish oil.
Spleens, but no horns
But are the much-maligned byproducts so bad? There's no definition for byproducts in the Australian pet food standard, but the definition supplied by the Association of American Feed Control Officials (AAFCO) states it "includes but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bone, partially defatted low temperature fatty tissue, and stomachs and intestines freed of their contents. It does not include hair, horns, teeth and hoofs".
In other words, it's the parts of an animal that a carnivore would normally eat, but are less popular with humans (although this can vary by culture).
Making pet food from the nutritious 'leftovers' of slaughtered animals makes use of what would otherwise be a waste product
From an environmental and animal welfare point of view, making pet food from the nutritious 'leftovers' of animals slaughtered for human consumption makes use of what would otherwise be a waste product to be disposed of – and prevents the need to raise and slaughter yet more animals.
The ingredient lists of some pet foods wouldn't look out of place on a wellness blogger's shopping list: kale, sea kelp, blueberries, cranberries, carrots, sun-cured alfalfa, emu oil, flaxseeds, salmon oil, green-lipped mussels, yoghurt, chicory root, dandelion and – yes – even coconut oil!
Ingredients that sound good to humans may in fact be less beneficial than ingredients that don't sound as good, and could just be a cynical attempt to justify the high cost of the food. As Adelaide vet Dr Andrew Spanner says: "Pets don't have wallets, people do. Marketers target pet owners by making foods that sound good and look good."
For many of these ingredients, there's no evidence they provide any benefit to your pet. Furthermore, some ingredients (the fruit and herbs, rather than the oils) are likely to be present in such small quantities as to be inconsequential, even if they did have a benefit. Too much of any fat, whether coconut oil, fish oil, emu oil or any other fat, can be dangerous to your pet and lead to pancreatitis.
There's a zoo in the pet food aisle! Bison, venison, wild boar, duck, emu and kangaroo are now found among the more commonplace beef, lamb and chicken. But these more exotic sources of meat offer no benefits over regular domesticated animals, and you may simply be paying for bragging rights.
A new source of protein?
On the other hand, if your pet develops an allergy to common meats, these more unusual variants could come in handy as a source of 'novel' protein that your pet hasn't had the chance to develop an allergy to – as long as they really are novel and you haven't already been feeding them to them. There may also be quality control and supply issues, which could affect safety, cost and availability.
Some premium pet food products may not contain all the nutrients needed for good health.
Foods labelled 'complete' are designed to provide a balanced diet for your dog or cat, and claim to meet the recommended nutritive requirements outlined by AAFCO. Foods that don't meet the minimum AAFCO guidelines should be labelled "intended for occasional or supplemental feeding", and should be fed alongside a complete food. You'll also see words like "treat" or "snack".
Buying complete cat food, especially wet food, is a minefield for the uninitiated
Buying complete cat food, especially wet food, is a minefield for the uninitiated. We surveyed a selection of cat food tins in 2017, only two of these similarly packaged tuna foods are complete: Fancy Feast's Classic and A La Carte recipes (the more expensive Royale is not).
Applaws 100% Natural range is not complete, where as some of their other ranges 'made with natural ingredients' are. As for Gourmet Delight, there's no information on the tin.
The Coles Complete Cuisine was, in fact, not complete. In 2017 we gave Coles a Shonky and referred them to the ACCC, as a result they cleared up their labelling.
Stock images: Getty, unless otherwise stated.