Meat From Endangered Sharks Found in Dog and Cat Food, Scientists Say

Scientists have identified meat from endangered sharks in a study of dog and cat food that may be fed to household pets without owners being aware of what it contains.

A DNA barcoding study conducted by scientists at Yale-NUS College in Singapore found that around a third of the pet food samples sequenced contained shark DNA, including from species considered "vulnerable."

The study also found that the products did not make clear that shark was included, instead describing the shark-based ingredient by using terms such as "white fish" or "ocean fish."

Ben Wainwright and Ian French of Yale-NUS College tested 45 pet food products for dogs and cats from 16 Singapore brands.

Of the 144 samples Wainwright and French sequenced, they found 45, or around one third, contained shark DNA.

Their study was published in the journal Frontiers in Marine Science on March 4.

The most commonly identified shark the scientists found was the blue shark, which has a "near threatened" conservation status due to overfishing, according to the International Union for Conservation of Nature (IUCN) Red List.

Two other species most frequently identified are considered "vulnerable" by the IUCN—the silky shark and whitetip reef shark.

The study also identified products containing DNA from the sicklefin weasel shark, the Caribbean sharpnose shark and the sand tiger shark. All three are considered vulnerable.

The scientists pointed out that estimates suggest oceanic shark and ray populations have declined 71 percent since 1970 "with these declines attributed to an 18-fold increase in fishing efforts."

The authors wrote: "None of the products specifically listed shark as an ingredient, listing only generic terms, such as 'ocean fish,' 'white fish,' and 'white bait.'"

"The vague terminology used to describe pet food ingredients, and in some cases, the mislabeling of contents, prevents consumers—in this case, pet owners—from making informed and environmentally conscious decisions; consequently, pet owners and animal lovers may unwittingly be contributing to the overfishing of endangered sharks," French and Wainwright said.

They noted later in the study that this labeling is not illegal but argued that "many pet owners and lovers would be alarmed to find out that they are likely contributing to the unsustainable fishing practices that have caused massive declines in global shark populations."

The scientists suggested that the shark meat may have ended up in the pet food because the meat was taken from shark carcasses when the animals' valuable fins were removed, noting that such a carcass is "a low-value product once the fins have been removed, it is possible that the pet food industry processes this carcass instead of wasting it."

French and Wainwright called for better labeling that avoided "vague catch-all terminology" and "would allow consumers to make more informed choices."

Composite Image Shows Shark and Puppy
A composite image shows a sand tiger shark and a border terrier puppy. A study has found shark DNA from several species in dog and cat food in Singapore. Getty Images