What are you feeding your pet? You may be in for a surprise. While the can may read 'beef', the chances are that what it actually contains is a mixture of several different meats.
New research from the University of Nottingham shows that as many as 14 out of 17 wet foods for dogs and cats contain proteins from animals not listed on the tin. These included cows, pigs and chickens.
Seven products prominently labelled 'with beef' turned out to have no more than 56% cow DNA; one had just 14%. Only two of the seven were found to contain more cow DNA than pig and chicken DNA combined. And even in the remaining five samples, three contained more pig than cow DNA.
The meat in Sainsbury's Basics Superchunks in Gravy with Beef for dogs, for example, consists of 47% beef, 52% chicken and 1% pork.
And of six labelled 'chicken' or 'with chicken', two contained more pig or cow DNA than chicken. Cooperative Gourmet Terrine with Chicken and Game contained just 1% chicken DNA.
All these descriptions, however, are perfectly legal.
"It may be a surprise to shoppers to discover that prominently described contents such as 'beef' on a tin could, within the guidelines, be a minor ingredient, have no bovine skeletal muscle (meat) and contain a majority of unidentified animal proteins" says Kin-Chow Chang, lead author of the report.
"There is a need for the pet food industry to show greater transparency to customers in the disclosure of the types of animal proteins in their products."
As the researchers point out, misleading labelling could cause problems for some pets and their owners. Some animals have food allergies, they say, and some owners could have religious concerns over the use of pig meat.
One good piece of news is that no horse DNA was tested. However, the researchers warn that they were only looking for cow, horse, pig and chicken DNA, meaning that there could still be other animals in the mix.
As a nation of animal lovers, the UK market for pet food is the biggest in the world, but is dominated by just two companies: Mars, which owns brands including Pedigree, Whiskas and Sheba; and Nestle, which owns Bakers, Go Cat, Purina and Winalot.
"Industry uses by-products from the human food chain and because of this, raw material supplies can vary during the year. Manufacturers may therefore use ingredients from different animal species based on supply levels," says the Pet Food Manufacturers' Association in a statement.
"All the materials selected are of equal quality and provide the same nutritional benefits to the animal."
Read more on AOL Money:
10 Tips for Cutting Pet Costs
Watch out for dog and cat fraud
Couple plans to leave everything to their pet monkey