Animal nutritionists have rubbished the exotic ingredients found in expensive pet foods as a marketing strategy designed to impress human owners while doing little if any good for their four-legged friends.

Hill’s, a pet food brand owned by Colgate-Palmolive and sold exclusively at vet clinics and pet shops, promotes a ‘science diet’ for pets.

The New Daily asked industry experts to analyse the long list of more than 40 ingredients in two of their products, Healthy Mobility for dogs and Optimal Care for cats.

Both products list beet pulp, cranberries, apples and vitamin C among many other ingredients.

But do these provide our animal companions any health benefits?

Nutritionist Dr Rosemary Stanton said she had no idea why Hill’s pet food contains so many ingredients.

“A strange list,” she told The New Daily.

Popular Hill’s products list more than 40 ingredients. Photo: Hill’s

“I would query why they add ‘colouring’ and beet pulp, which is from sugar beet and contains sugar.

“I noticed they include vitamin C, but dogs make their own!

“The list looks as though it is designed to appeal to the humans who purchase the food.”

She said industry insiders told her that some products sold in pet food shops can cost consumers five to 10 times more than products “with no particular benefits”.

“There is no problem with dog food containing offal – liver, kidneys and heart are all highly nutritious,” Dr Stanton said.

“The important things for owners to note are the amount of protein, fat and fibre. Dogs need protein and fat, but don’t really need a lot of dietary fibre.”

US nutrition professor and co-author of Feed Your Pet Right, Marion Nestle, questioned the nutritional value of the ingredients at the end of the list – apples, broccoli, carrots, cranberries and green peas.

“These would be in such small amounts that their purpose must be marketing, not nutrition,” she said.

The ingredients also include added vitamins and minerals.

Clare Kearney, a holistic animal nutritionist, said she was not confident what are most often synthetic vitamins would provide any real nutritional benefit.

However, food science expert Dr Elham Assadi Soumeh said cranberries and vitamin C could provide health benefits.

“Cranberries are a good source of antioxidants, and commercial dog foods contain vitamin C, presumably because of its natural antioxidant properties,” she said.

Despite repeated requests from The New Daily, Hill’s refused to comment on its ingredients and nutritional claims.

Health impacts of processed pet food

Nutritional ecologist David Raubenheimer said that he was concerned about cats being fed vegetables and grain because they are carnivores, as opposed to the more omnivorous dogs.

“Adding fruits and vegetables to cat foods will dilute protein with carbs,” he told The New Daily.

“We know that cats have a limit for tolerating dietary carbs, and also that processed cat foods have higher carbs and lower protein compared to the diets of hunting cats.

“Fruits will also add fibre. In the wild, predators like cats don’t eat plant-derived fibre, but they do eat animal-derived fibre like fur and bones.”

Professor Raubenheimer said there is a strong need for more research into the implications of feeding pets highly processed foods.

He said the impact of processed foods on a pet’s health could be potentially more significant than that on a human’s health, as many pets are fed a diet entirely of processed products.

“We know that processed foods are a major contributor to the many health problems in humans, and an obvious question is: why this shouldn’t be the same for pets?” he said.

“What does the processing aim to achieve? The short answer is ‘profit’.

“Unfortunately, for humans this boils down to processed foods that are engineered primarily to be cheap, tasty and convenient, with little or no real concern for health.”

A Senate inquiry is currently considering possible regulatory approaches to ensure the safety of pet food in Australia.