Pet food

Are the claims made by pet food manufacturers more bark than bite?

16oct pet food hero1

We want the best for our furry friends – and pet food manufacturers are falling over themselves to offer it.

Shop shelves are groaning with products promising to “nourish your pet as nature intended” and “provide every dog and cat with the nutrition that is precisely right for their individual needs”. We’ve looked into whether you should consider these claims when choosing a pet food.

Mars Petcare US, the manufacturer of Eukanuba dog food, crossed the line last year. In US-based ads, the company stated a 10-year study showed labradors fed Eukanuba lived 30 percent longer.

The lab results were false.

The study showed no difference between labradors fed Eukanuba and the general labrador population. Mars Petcare agreed to settle Federal Trade Commission charges it had falsely advertised the benefits of its product.

What to look for

If you’re hunting for a good pet food, look for products that reference a feeding trial or nutrient profile developed by the Association of American Feed Control Officials (AAFCO). You’ll find the reference on the product’s packaging or the manufacturer’s website.

AAFCO maintains the nutritional standards for pet food sold in the US. But the standards are internationally recognised.

Pet foods that meet these standards can claim they’re complete and balanced. “Complete” means the food has all the nutrients required to sustain your pet. “Balanced” means the nutrients are present in the correct ratios.

According to the association, cats and dogs share the same life stages:

  • Growth (kittens and puppies)
  • Gestation and lactation (pregnancy and nursing)
  • Maintenance (adulthood).

You should buy a food that’s either formulated for your pet’s life stage or suitable for all life stages. In particular, a bouncy kitten or puppy needs nutrients in different ratios to an adult pet.


For many owners, cats and dogs have made the leap from pets to family members. Manufacturers have lapped up this transition. Pet foods are now crammed with ingredients to satisfy human sensibilities: low glycaemic carbohydrates (to prevent obesity), “delicate” sauces, “tempting” gravies, health promoting botanicals and so on. But which claims should be taken with a pinch of salt?

Senior pets

There’s no AAFCO life stage for senior pets. Nevertheless, major manufacturers produce foods for older cats and dogs.

According to Massey University’s Nick Cave, a senior lecturer in small animal medicine and nutrition, the problem is animals age at different rates based on breed, activity, environment and other factors. This means it’s implausible to formulate a product for all dogs over the age of seven or all cats over the age of 11.

Older dogs, for instance, may need fewer calories because of decreased activity. But the age when a dog’s activity decreases can differ between individuals. “There is no single nutritional recommendation that makes sense for all elderly animals,” Mr Cave says. If you think your ageing pet needs a change in diet, talk to your vet.

Light products

Fat pets are more likely to suffer from arthritis, heart disease, high blood pressure and diabetes. To combat obesity, manufacturers have formulated “weight management” or “light” pet foods, which have less calories than their standard formulations.

But these products alone are unlikely to solve your pet’s obesity problem. Overweight animals need the same lifestyle changes as overweight people – fewer calories, more exercise.

As both factors are within your control, you can tackle your pet’s weight by giving it less food at meal times and upping its activity levels (for instance, encouraging your cat to chase a piece of string). If treats are a problem, set aside a portion of your pet’s usual breakfast to use throughout the day.

Joint disorders

Some pet foods tout glucosamine, chondroitin sulphate, omega-3 fatty acids and green-lipped mussels to support joint health and mobility.

But the biggest factor when it comes to joint health is your pet’s weight. “You can minimise the risk of osteoarthritis in your pet by ensuring it’s not overweight,” Mr Cave says. “If your pet is overweight and suffers from arthritis, then getting it to lose weight will have a profound effect on the amount of pain it endures.”

Dental health

Most cats and dogs have some periodontal (gum) disease by the time they’re three years old. Periodontal disease is caused by the build-up of plaque and tartar in your pet’s mouth.

The best way to reduce plaque is to brush your pet’s teeth on a regular basis. If that’s a stretch, you can give your pet a dry food or toy to chew on. Some dry foods claim they’re manufactured to scrape more plaque off your pet’s teeth with each bite.

To detect problems, you should also get Fluffy’s teeth checked by a vet once a year. Some pet insurers won’t cover the cost of dental treatment unless your pet has had its teeth checked by a vet in the past 12 months.

Grain-free diets

Red meat, poultry and their by-products are typically the main ingredients in standard pet foods. These are followed by grains such as maize and rice.

The marketing material for grain-free pet foods often states domestic cats and dogs are descended from wild animals and, therefore, can’t handle carbohydrate-loaded foods. Among other concerns, grains purportedly cause allergies in pets.

In fact, cats and dogs can digest grains, which contribute energy and nutrients to their diets. While it’s true pets occasionally suffer food allergies, these may be caused by a number of ingredients, including animal proteins and grains.

“We’ve looked hard for evidence that feeding pets a diet high in carbohydrates causes disease, but we’re yet to find any,” Mr Cave says.

Raw meat-based diets

Like grain-free diets, raw meat-based diets are built on the premise cats and dogs should eat like their wild ancestors. Advocates say pets fed raw diets (which can include ingredients such as raw eggs, fruit and veges) have shinier coats, cleaner teeth and better general health.

According to the American College of Veterinary Nutrition, evidence of these benefits is restricted to testimonials. Some studies have shown pets find raw meat slightly more digestible than cooked meat. But this benefit can be offset by drawbacks, it says. For instance, raw meat-based diets can be nutritionally imbalanced – they can contain either too little or too many key nutrients – when not prepared correctly.

If you want to buy your cat or dog a commercial raw pet food, pick a product formulated to meet AAFCO requirements. Not all of them fit the bill.

Separate formulas

Pet food manufacturers like breaking up the market into segments. For instance, Eukanuba’s website lists 29 dry foods and 18 canned foods for dogs. These are categorised by life stage, breed and special needs, such as sensitive joints.

There’s minimal difference between some products. Eukanuba’s Adult Large Breed, Adult Medium Breed, Golden Retriever and Boxer formulas contain the same 16 ingredients (dried chicken and turkey, maize, wheat and so on) in different ratios. But as a golden retriever is a large breed of dog, are separate formulas really necessary?

Masterpet, the New Zealand distributor of Eukanuba, agrees the ingredients are similar for its large breed diets. It says recipes are tailored where it identifies “specific nutritional needs”.

16oct pet food reg vs breed

Like Eukanuba, Hill’s Pet Nutrition targets products at different market segments. Some of the company’s products contain identical formulas, but are sold at different prices. For instance, Hill’s Science Diet Perfect Weight Adult (for dogs) has the same ingredients as Perfect Weight Small and Toy Breed Adult, right down to the trace elements. The food for small dogs is $2 more expensive than the standard food, even though both come in 1.81kg bags. The difference? The kibbles for small dogs are, well, smaller.

Supermarket vs pet store products

Most cat and dog owners buy their pet food from supermarkets. Many of these products have undergone AAFCO feeding trials, and some contain similar ingredients to pricier products from pet stores.

16oct pet food supermarket vs pet store

We bought a bag of Purina One SmartBlend Chicken and Rice Formula for dogs from Countdown, and compared it with a bag of Purina Pro Plan Savor Adult Shredded Blend Chicken and Rice Formula from Animates. The latter is $11 more expensive ($41.90 vs $30.99) and comes in a smaller bag (2.72kg vs 3.63kg). So what do you get for the extra outlay?

Both products boast chicken as the main ingredient. The next eight ingredients are the same in slightly different ratios: brewers’ rice, whole grain wheat, poultry by-product meal, soybean meal, corn gluten meal, animal fat and whole grain corn. According to the packets, the products have strikingly similar nutritional make-ups and calorie content. We found similar points of comparison in the Purina One and Pro Plan cat foods we bought.

Purina New Zealand says the Pro Plan range has additional nutrients when compared with the One range – but these nutrients aren’t considered essential by AAFCO.

Standard vs premium products

Expensive pet foods are more likely to claim real meat and poultry as their main ingredient. Standard foods may substitute meat by-products (think organs and blood) for muscle meat and incorporate a higher percentage of grains, such as rice and wheat.

16oct pet food premium vs standard

We compared a 2.5kg bag of ZiwiPeak Daily-Dog Beef Cuisine Recipe with a same-sized bag of Purina Tux Meaty Recipe Adult Small Biscuits. The first bag cost $89.75 and the second cost $11.99. While both products are complete and balanced, ZiwiPeak consists mostly of beef meat and organs whereas Tux lists cereal as its main ingredient, followed by meat and animal by-products.

ZiwiPeak has double the minimum crude protein of Tux, almost five times the minimum fat and a whopping 4910 kilocalories per kg. On average, a 25kg dog only needs 222g of ZiwiPeak per day compared with 390g of Tux. ZiwiPeak’s smaller portion sizes, coupled with lower levels of crude fibre, mean there’s less waste to pick up once your pooch has finished digesting its dinner. But these benefits come at a price. It costs ruff-ly $8 per day to feed a 25kg dog ZiwiPeak vs $1.90 to feed it Tux.

AAFCO standards

To meet AAFCO’s definition of “complete and balanced”, pet food manufacturers must either put their product through a controlled feeding trial or formulate their food to meet a prescribed nutrient profile.

Feeding trials are the most accurate means of determining a pet food’s nutritional adequacy. Here, a colony of cats or dogs is given the test food as its sole diet. The colony’s health is monitored for any nutritional deficiencies. If the product is up to scratch, it can claim on its label: “Animal feeding tests using AAFCO procedures substantiate that [product X] provides complete and balanced nutrition for [all life stages or a specific life stage].”

Nutrient profiles allow manufacturers to formulate products that, on paper, should provide a complete and balanced diet. This method is cheaper and quicker than feeding trials. Pet foods that meet this mark can claim: “[Product X] is formulated to meet the nutritional levels established by the AAFCO Food Nutrient Profiles for [all life stages or a specific life stage].”

There’s a third AAFCO statement, which sometimes appears on pet food “families” with the same nutritional basis, but minor formulation changes. It reads: “[Product X] provides complete and balanced nutrition for [all life stages or a specific life stage] and is comparable to a product which has been substantiated using AAFCO feeding tests.”

By the numbers

By the numbers

16oct pet food by numbers promo

By the numbers

Earlier this year, the New Zealand Companion Animal Council released the results of a survey on pet ownership in New Zealand. Here are some of the findings:

  • 64% of Kiwi households own a pet, second only to the US at 65%.
  • 58% of people who don’t own a pet would like one.
  • 1.134 million cats in New Zealand vs 683,000 dogs.
  • $670 per year spent on each cat vs $1200 per year on each dog.
  • $787 million the estimated spend on pet food in 2015.
  • 93% of cat owners and 88% of dog owners feed their pets commercial dry pet food (most of which is bought from supermarkets).

Member comments

Get access to comment

Llyvonne B.
25 Nov 2018
Raw diet

I have a small terrier and he has had a raw diet since he was a puppy - primarily human grade chicken (fed raw, with bones - important that there is no cooked chicken bones). He has had no problems with this diet. He is currently 12 and is active and have very few visits to the vet - and the majority are for annual check ups. I notice that my dog does not have the smelly breath or poop that is found with dogs that eat commercial dog food.
I have found out that it is important to be very careful with larger bones - especially with smaller dogs. These bones should be monitored because if a piece breaks off and the dog swallows it, it can cause a blockage. Also, large bones (e.g. beef leg) may damage the teeth of small dogs - so you do need to think about suitability.

Ray A.
24 Jan 2021
Wheat, corn and grains

Since when did dogs eat cereals? Their natural diet is meat and greens. My vet says: 80% greens e.g. silver bee and 20% meat.

William B.
02 Aug 2017
Cat likes and dislikes

It doesn't matter what pros and cons for the product, our cat will only eat one soft food and one brand of crunchy biscuits. It took us months of experimenting, but we finally found the right ones and she is doing well. So much for "Best of", although both are good brands, so I guess no harm done.

Previous member
29 Oct 2016
Raw meaty bones

Our kelpie cross bitch died last year at the grand old age of 17. For the last 14 years of her life we fed her raw meaty bones and she thrived. No more trouble with vomiting and smelly dog smell or horrible poo. Her teeth were good to the end and praised by the vet. There is a vet in Oz who has written a book on the subject and he was visiting NZ and was talking on the radio. Everything he said made good sense and we became converts. If you Google raw meaty bones you can read all about the diet.

Laraine B.
05 Nov 2016
We give our dogs bones too

Those big things packed in plastic wrap that you can buy from Pak'n'Save for $1.99 (they used to be $1). But we do it mainly for their teeth rather than diet. The bones are nearly as big as they are so each dog gets put in a pen for 1/2 to 1 hour, on an average of 3-4 days per week. The bone seems to last that long.

Nyla S.
29 Oct 2016
Dog Food Allergy

My shitzu get allergies from most biscuits, the food thats working a treat for her now is the Tux medium triangle at breakfast, this she chomps away on and hopefully is cleaning her teeth, for dinner she has Butch sausage Gold/white and vegy. every so often I give her a raw egg or wheetbix and milk ... no scratching and eating herself raw now ... touch wood !!!

Nyla S.
14 Nov 2016
shitzu with allergies

my wee girl also was scratching and chewing herself to bits ... I heard about butch gold/white and I also gave tux med triangles ago with added vegy, sometimes egg, and sometimes weetbix and milk ... and great, she no longer has a problem ... highly recommend these tips