Mystery meat DNA shows up in pet food

"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," says Kin-Chow Chang. (Credit: Steven Mileham/Flickr)

Several brands of pet food from UK supermarkets contain unspecified species of animals and proportions of beef, chicken, and pork that don’t line up with the label on the can.

Researchers from the University of Nottingham determined the relative presence of DNA from cow, chicken, pig, and horse in 17 leading brands of dog and cat wet food.

They then compared their results with the animal species details on the pet food labels.

‘With beef’

While no horse DNA turned up, a major finding was the relative abundance of proteins from unspecified animal species in 14 of the 17 products.

Among these 14 samples, scientists found cow, pig, and chicken DNA in various proportions and combinations that were not explicitly identified on the product labels.

Seven products with prominent descriptions containing the term “with beef” comprised between 14 percent and 56 percent of cow DNA. Only two of the seven were found to contain more cow DNA (>50 percent) than pig and chicken DNA combined. With the remaining five samples, three contained more pig than cow DNA.

Another six headline labels that highlighted “chicken” or “with chicken” contained 1 to 100 percent of chicken DNA. Two products contained more pig or cow than chicken DNA.

Consumer surprise

While the present practice in pet food labeling is within current regulatory guidelines, the findings highlighted weaknesses in product labeling that could adversely affect pets and their owners’ expectations.

“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 lead author Kin-Chow Chang of the University of Nottingham.


“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.

“Full disclosure of animal contents will allow more informed choices to be made on purchases which are particularly important for pets with food allergies, reduce the risk of product misinterpretation by shoppers, and avoid potential religious concerns.”

The study is limited by the relative amount of DNA detected for each host species calculated as a percentage of total detected DNA. This means that the figures do not represent the species DNA content as a percentage of the entire product. This is because DNA from species other than cow, horse, pig, and chicken would not have been recognized.

The article is available in the journal Acta Veterinaria Scandinavica.

Source: University of Nottingham