Farmed Carnivores May Become Hidden “Disease Reservoirs” Posing Risk to Human Health

Mink Fur Farm

Carnivorous animals lack key genes needed to detect and respond to infection by pathogens, a study has found.

Farming large numbers of carnivores, like mink, could allow the formation of undetected ‘disease reservoirs,’ in which a pathogen could spread to many animals and mutate to become a risk to human health.

Research led by the University of Cambridge has discovered that carnivores have a defective immune system, which makes them likely to be asymptomatic carriers of disease-causing pathogens.

“We’ve found that a whole cohort of inflammatory genes is missing in carnivores.” — Clare Bryant

Three key genes in carnivores that are critical for gut health were found to have lost their function. If these genes were working, they would produce protein complexes called inflammasomes to activate inflammatory responses and fight off pathogens. The study was published recently in the journal Cell Reports.

The researchers say that the carnivorous diet, which is high in protein, is thought to have antimicrobial properties that could compensate for the loss of these immune pathways in carnivores – any gut infection is expelled by the production of diarrhea. But the immune deficiency means that other pathogens can reside undetected elsewhere in these animals.

“We’ve found that a whole cohort of inflammatory genes is missing in carnivores — we didn’t expect this at all,” said Professor Clare Bryant in the University of Cambridge’s Department of Veterinary Medicine, senior author of the paper. 

She added: “We think that the lack of these functioning genes contributes to the ability of pathogens to hide undetected in carnivores, to potentially mutate and be transmitted becoming a human health risk.”

Zoonotic pathogens are those that live in animal hosts before jumping to infect humans. The DOI: 10.1016/j.celrep.2021.109614

This research was funded by Wellcome.