A major new study published in Science has analysed four decades of global wildlife trade data. Its conclusion is difficult to ignore: traded mammals are substantially more likely to share pathogens with humans than mammals who are not traded.
This is not a problem with a few illegal markets. It is not limited to badly regulated traders, poor hygiene or one country. The trade itself creates the contact that allows viruses, bacteria, fungi and parasites to move between species. We already know the consequences can be catastrophic. The exploitation and trade of wild animals have been implicated in outbreaks including SARS, Ebola, mpox and COVID-19. But animals continue to be captured, bred, warehoused, transported and sold for food, medicine, fashion, entertainment, tourism and private captivity. We are manufacturing opportunities for disease.
Forty Years Of Evidence
Researchers examined more than 6,000 mammal species, including 2,079 who had been recorded in trade. They combined legal trade records, United States import data, international seizure records and a database of mammal pathogens.
Among traded mammals, 41% shared at least one pathogen with humans. Among mammals not recorded in trade, the figure was just 6.4%. Some of this difference could be explained by other factors. Species living near humans are studied more often. Animals consumed as food may face more direct contact. Closely related species can host similar pathogens.
Geography also matters. The researchers accounted for these influences, including the amount of scientific attention devoted to each species. Even after doing so, traded mammals were still around 1.5 times as likely to share pathogens with humans.
The strongest predictor was not whether an animal was eaten, lived near human settlements or appeared in illegal trade. It was whether that species was traded at all.
Time made the problem worse. On average, a wild mammal species shared one additional pathogen with humans for every decade spent in the global trade.
The longer we exploit a species, the more opportunities we create for pathogen exchange.
Legal Does Not Mean Safe
Politicians often divide the wildlife trade into two neat categories. Legal trade is presented as controlled and responsible. Illegal trade is blamed for cruelty, extinction and disease. The evidence does not support that comforting distinction.
Animals traded alive were 34% more likely to share pathogens with humans than animals traded only as body parts or products. They also shared around 50% more pathogens on average.
Species appearing in illegal trade were not significantly more likely to share at least one pathogen, but they shared 40% more pathogens than species traded only legally. Illegal routes can intensify the danger, but legality does not remove it.
The legal trade still involves capture, breeding, confinement, handling, transport, storage, markets and close contact with humans. Every stage creates another chance for infection to pass between bodies.
A licence does not stop a virus.
The Exotic Animal Trade
The trade in wild companion animals is a major part of this system. An investigation into trafficking from Latin America to Europe identified 2,495 animals across 69 species in just 34 reported seizures between 2017 and 2023. Around 94% were alive. Amphibians made up most of those seized, followed by birds and reptiles. These figures represent only the shipments authorities found and the media reported. Officials believe much larger volumes may move through ordinary air cargo, sometimes using false documents or exemptions intended for zoos.
Europe is not merely a transit route. It is a consumer market.
Rare frogs, songbirds and reptiles are removed from biodiverse regions and transported across continents because European buyers want something unusual in a tank, cage or enclosure. Some animals are hidden in luggage. Birds have been forced into toothpaste boxes. Lizards have been sewn into dolls.
Others enter through apparently legitimate commercial channels.
Only a quarter of the species identified in the European investigation were protected by the Convention on International Trade in Endangered Species. Animals may be protected in the country where they were taken, yet fall into a legal gap when they reach Europe.
Scarcity becomes a sales feature. Endangerment increases prestige. A species can be disappearing in the wild while buyers compete to possess one.
Even people who claim to care about conservation can help drive this demand. In one international survey, most respondents said they preferred captive-bred animals who were common in the wild. But 30% said they would probably buy an animal before a trade ban came into force.
The threat of protection can trigger a buying rush.
Captive-Bred Is Not The Answer
The industry presents captive breeding as the ethical alternative to taking animals from the wild. This ignores both the scale of commercial wild animal farming and the harms built into captivity itself.
Researchers identified at least 487 wild animal species farmed commercially across 90 countries between 2000 and 2020. They estimated that between 936 million and 964 million individual animals were farmed during that period.
The real total is likely far higher. The estimate excluded wild fishes and invertebrates, while government records were incomplete, inconsistent or unavailable. A separate CITES database recorded 1,792 commercially farmed wild species in international trade.
Wild animals are bred for fashion, medicine, luxury food and private captivity. Farming can also increase demand, provide cover for animals taken illegally from the wild and require new animals to replenish breeding stock.
Most importantly, being born in captivity does not turn a wild animal into a domesticated one.
A ball python does not need less space because a breeder produced them for sale. A parrot does not lose the need to fly, socialise and make choices because paperwork describes them as captive-bred.
Captive breeding changes an animal’s birthplace. It does not erase their nature or make confinement justifiable.
The Cost To Animals
Disease risk is only one consequence of the trade.
Animals may be denied suitable food and water, exposed to extreme temperatures, packed into filthy containers, injured during capture and left without treatment. They may spend their lives unable to move properly, hide, fly, climb, swim, forage or interact with members of their own species.
Ball pythons are kept in enclosures too small for them to extend their bodies. African grey parrots are caught using glue. Pangolins are tied inside net sacks. Frogs have their legs cut off while conscious. Sharks have their fins removed before being thrown back into the sea. Young elephants are separated from their mothers and subjected to violent training for tourism.
This is not a collection of isolated abuses. These are predictable consequences of turning living beings into products. The global trade is so poorly monitored that nobody knows how many animals are involved. CITES records counted almost 54 million wild vertebrates and 36.5 million invertebrates traded between 2005 and 2014, but wider estimates suggest billions are exploited every year. The missing data does not show that the problem is small. It shows how little scrutiny the industry faces.
Enforcement Is Not Enough
New technology may help authorities identify some trafficked animals. Researchers in Australia recently trained artificial intelligence to detect shark fins, seahorses and sea cucumbers in 3D X-ray scans, with success rates between 85% and 95%. This could help border staff intercept hidden shipments. It does not address why those shipments exist.
Wild animals and their body parts are openly advertised on mainstream social media. A BBC investigation found tiger teeth, bones, live cubs, pangolin scales, rhino horn, shark fins and dried seahorses offered through Facebook.
A UK supplier posted 15 dead seahorses directly to an investigator with no documentation. Three were pregnant males, each of whom may have been carrying hundreds of young.
Global enforcement operations seize tens of thousands of living animals and tonnes of body parts. Yet every seizure reveals only a fraction of the trade. Algorithms, sniffer dogs, border officers and stronger databases may make trafficking harder, but they cannot make the commercial exploitation of wild animals safe or ethical.
Regulation usually asks whether animals survived the journey, whether the correct form was completed and whether a species can withstand continued extraction. It rarely asks the obvious question.
Why are we trading wild animals at all?
Close The Door
The new study calls for stronger biosurveillance and reforms to international trade rules. Those measures may reduce some immediate risks. The researchers also acknowledge that reducing the number of animals in trade will be necessary to prevent future pathogen emergence.
We should go further.
The wildlife trade harms individual animals, threatens species, destabilises ecosystems and creates routes for diseases that can kill humans on a global scale. These are not unrelated side effects. They all emerge from the same decision to treat wild animals as resources, products and possessions.
The UK should stop importing exotic animals for private captivity, whether they were captured from the wild or bred on commercial farms.
At time of writing more than 6,200 people have already signed the petition calling on the UK Government to ban these imports. Add your name and help close the door on a trade that should never have been normalised. Wild animals belong in their own habitats, living for their own purposes. Not in our homes. Not in our markets. Not in our supply chains.
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