(Bloomberg) -- Novel and potentially dangerous viruses, including coronaviruses and influenza, are harbored in raccoon dogs, mink and other animals farmed for fur in China, scientists found in the first in-depth investigation of the seldom-studied critters.
Researchers scoured for viruses in the lungs, intestines and other tissues of 461 individual fur animals that were found dead due to disease across China. They identified 125 virus species, including 36 that were novel and 39 at potentially-high risk of crossing the species barrier, including spilling over to infect humans.
Raccoon dogs and mink, valued for their soft pelts, carried the highest number of potentially dangerous viruses, according to the research, published Wednesday in the journal Nature.
“Asia is one of the most active regions for fur-animal farming and trading,” the authors, led by Shuo Su at Shanghai’s Fudan University, wrote. “Despite this, little is known about the viruses that circulate in fur animals in this region.”
Virus-related research on farm animals has focused disproportionately on conventional livestock, like pigs. However, fur animals are raised in many countries to supply a market worth over $15 billion. China dominates the trade, accounting for over 80% of global fur production, with pelts from around 27 million animals turned into high-end garments in 2021.
Notably, 19 potentially high-risk viruses were detected in the northeastern province of Shandong, which contains many fur animal farms. The findings revealed potential virus transmission between farmed animals and wild animals, and from humans to farmed animals, indicating that fur farming represents an important transmission hub for viruses that risk causing disease in people.
Intensive Farming
“The intensive breeding environment of farmed animals serves as a possible bridge for virus spillover,” the researchers said. “As humans regularly come into contact with farmed animals, it is critical to improve our knowledge of the viruses that circulate among farmed fur animals and their potential for zoonotic transmission.”
The study identified seven species of coronaviruses, expanding the known host range of the species responsible for the Covid-19 pandemic. It also documented the cross-species transmission of a novel canine respiratory coronavirus to raccoon dogs and of bat coronaviruses to mink that was found in high abundance in lung tissues.
Fur animals such as foxes, civets and mink have been implicated as potential hosts for a variety of human viruses, including flu, the original SARS coronavirus and SARS-CoV-2, the virus that set off the pandemic at the end of 2019. While scientists have yet to understand Covid’s origins, live raccoon dogs were sold in a Wuhan wet market that was tied to many of the earliest human infections, and are viewed as a potential source.
Three strains of influenza virus — H1N2, H5N6 and H6N2 — were detected in the lungs of guinea pigs, mink and muskrats, respectively, in the new study.
More regular surveillance of these animals — especially mink, raccoon dogs and guinea pigs — is needed to evaluate the potential risks to public health that stem from fur-animal farming, the authors said.
--With assistance from Karoline Kan.
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