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Monday, January 25, 2021

Utah Officials Allegedly Failed to Disclose Mink Farm Worker Died of COVID After Outbreak

Amid ongoing debate over the threat posed by COVID-19 outbreaks on mink farms, state authorities in Utah allegedly failed to disclose the COVID-19 death of a mink farm worker linked to a coronavirus outbreak at a mink farm in the state.
© Ole Jensen/Getty Images Mink at the Knud Vest estate in Jyllinge, Denmark, pictured on November 14, 2020. State authorities in Utah allegedly failed to disclose the COVID-19 death of a mink farm worker linked to a mink farm coronavirus outbreak in the state.

The Utah Department of Agriculture and Food (UDAF) has also allegedly not been transparent about COVID-19 transmission in the wild and downplayed the threat mink farm COVID-19 outbreaks pose to humans, animal rights groups claim.

Scientists have previously warned the diseased mink could create a new uncontrollable store and vector for the transmission of coronavirus to humans and potentially pose a risk to future COVID-19 vaccines.

The mink farm outbreaks in Utah, which marked the country's first confirmed cases of COVID-19 infection in mink, were announced in statements released by the UDAF as well as the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) on August 17, 2020.


According to an email shared with Newsweek, which was among several documents obtained by an open records request made by the Utah Animal Rights Coalition (UARC) who shared the files with Direct Action Everywhere (DxE), an animal rights network based in the San Francisco Bay Area, "one farm manager has died from SARS-CoV-2 infection" following the coronavirus outbreaks at two mink farms in Utah back in August.

Neither of the August statements released by the UDAF and USDA APHIS mentioned the death of the mink farm manager noted in the aforementioned email, which was sent on August 10, 2020, a week before the statements were released by the UDAF and USDA.

Speaking to Newsweek, Wayne Hsiung, an attorney and investigator for DxE, which he co-founded, said: "The document [the email] was obtained through the state of Washington because the lab that did the testing for Utah mink farms was a public university in Washington. The state of Utah itself has refused to make these disclosures, citing the risk of break-ins by animal rights activists (including specifically DxE), and has never disclosed the site of any outbreaks, much less that an employee died."

In a blog post on the DxE website where the documents obtained by the open records request were published on Monday, Hsiung explained: "Given Utah's stonewalling, our partner groups submitted an open records act request to Washington State University [WSU], a public institution that is home to the Washington Animal Disease Diagnostic Library (WADDL), which carries out laboratory testing for the USDA and other agencies."

WSU released a set of documents including an email from Tom Baldwin, the director of the Utah Veterinary Diagnostic Laboratory (UVDL) at Utah State University who was the veterinarian investigating the COVID-19 outbreaks on the Utah mink farms at the time, according to Hsiung.

UVDL is "a cooperative effort by Utah State University (USU) and Utah Department of Agriculture and Food (UDAF)," according to its website.

Baldwin's email, which was sent to WADDL Executive Director Timothy Baszler and WADDL Director of Operations Kevin Snekvik, stated: "We have a number of mink farms in which adult mink are dying at concerning rates. Moreover, farm personnel are experiencing upper respiratory infections and one farm manager has died from SARS-CoV-2 infection."

As indicated in the email, Utah State Veterinarian Dr. Dean Taylor, who works for the UDAF, was copied in Baldwin's email.

Hsiung told Newsweek: "The state veterinarian of the UDAF is cc'd [copied] in the correspondence. Given his role in protecting public health, one can assume that he knew about this death—and has chosen to not disclose it in the various public communications."
What Utah state health department and CDC say

Asked whether the Utah Department of Health (UDOH) was aware of the death of the Utah mink farm manager, as well as several other questions relating to that death, a public information officer at the UDOH told Newsweek that the department has been involved in an "on-going, collaborative response and investigation" of the Utah mink farm COVID-19 outbreaks with the UDAF, CDC and USDA APHIS.

"This investigation resulted in the link of an individual who recently passed from COVID-19 and who happened to be employed at the mink farm. At the time the person became ill, community spread had been increasing rapidly in the surrounding area. No additional deaths associated with mink farms have been reported. Currently, there is no evidence of mink-to-human transmission in the United States.

"All human lab-confirmed COVID-19 cases are routinely reported to UDOH through normal channels. Confirmed COVID-19 cases are interviewed by a contact tracer and appropriate quarantines are recommended. When a person in Utah dies and has tested positive for COVID-19, the death is investigated and the cause is determined by the Office of the Medical Examiner. All of these normal reporting and response steps occurred in this particular instance.

"In August of 2020, the Utah Department of Agriculture and Food (UDAF) notified the UDOH of an unusually high rate of mink mortality on a Utah farm, along with the suspicion that the mink deaths might be related to SARS-CoV-2, the virus that causes COVID-19 in humans. Our federal partners were immediately notified and Utah invited CDC to deploy a team of One Health experts to assist with on farm investigations of SARS-CoV-2 in people, mink, and other animals on affected Utah mink farms. Our federal partners have continued to support UDAF and UDOH in this on-going investigation and response.

"In response to these outbreaks, UDOH conducted epidemiologic investigations on any mink farm with a confirmed case of SARS-CoV-2 among their herds. From these investigations, it is suspected that infected workers introduced SARS-CoV-2 to the farms, and the virus then spread between mink. All epidemiologic evidence and test results indicate human-to-mink transmission with a person with COVID-19 infection introducing the virus onto each farm," the UDOH public information officer said.

Asked the same questions about the farm employee death, as well as why the manager's death was not mentioned in the August 17 USDA statement, a spokesperson for USDA APHIS told Newsweek: "USDA's Animal and Plant Health Inspection Service (APHIS) has worked closely with the U.S. Centers for Disease Control and Prevention (CDC) and individual states, including Utah, throughout the COVID-19 outbreak to identify animals that should be tested, develop and recommend guidance for contact with animals, and to determine how to handle cases when they are confirmed in animals.

"APHIS' focus is on the health of animals in the United States, and our primary role is testing samples from animals and reporting confirmed cases to the World Organization for Animal Health (OIE). While we work closely with these partners on the overall response, it would be inappropriate for APHIS to maintain information about or comment on cases of COVID-19 in people. Your questions would be better directed to CDC [U.S. Centers for Disease Control and Prevention] or the Utah Department of Health," Cole added.

When the CDC was asked the same questions relating to the mink farm worker death, including whether the UDOH had reported that death in the state's COVID-19 death totals and shared any information about that death with the CDC, a spokesperson for the federal health body told Newsweek: "CDC defers to the Utah Department of Health to provide details on human COVID-19 cases linked with mink farms in their state. CDC has been collaborating with human and animal health officials in Utah and USDA regarding mink farms with SARS-CoV-2 since August 2020.

"Currently, there is no evidence of mink-to-human spread in the United States, however investigations are ongoing. Although, human cases have been identified in connection with all affected U.S. mink farms. It is suspected that infected workers introduced SARS-CoV-2 to mink on the farms, and the virus then began to spread among the mink and from mink to other animals like cats and dogs on the farm. Although for most people in the United States the risk of SARS-CoV-2 infection from animals is low, there is a higher risk for people working on mink farms," the spokesperson added.

Newsweek has contacted the UDAF, Taylor and Baldwin for comment.

Asked whether there was any further information available about the death of the Utah mink farm manager, including how the employee got infected, Hsiung told Newsweek: "No. And unless public health authorities were conducting prospective genomic surveillance among the mink and the workers, we will likely never be able to definitively answer this question.

Hsiung explained in Monday's DxE blog post: "We cannot be sure the farm manager at issue died from mink transmission, given that the state of Utah has not disclosed any genomic testing at this site or any other site.

"But it appears that those investigating the outbreak were alarmed at the rate of infection among workers on these farms, and this is supported by peer-reviewed research from the Netherlands showing that 68 percent of mink farm workers and their close contacts had evidence of SARS-CoV-2 infection, a far higher rate of infection than the general population," he told Newsweek.
COVID-19 transmission in the wild and threat to humans

Last April, the Netherlands became the first country in the world to report COVID-19 cases among mink.

In a statement on May 19, 2020, the Dutch government said: "New research findings in the ongoing investigation into COVID-19 at mink farms suggest there has been a transmission of new coronavirus from mink to human."

Hsiung noted in the Monday DxE blog post: "Even Fur Europe, an umbrella organization representing the European fur industry, circulated an alert acknowledging this new development, writing on May 26 to its members that the coronavirus is 'transmissible from human to mink, and likely transmissible back to humans again.'"

But the UDAF has allegedly downplayed the threat mink farm outbreaks pose to humans and claimed there was no COVID-19 transmission in the wild, according to the UARC and DxE.

Speaking to Newsweek, UARC Executive Director Jeremy Beckham, who made the aforementioned open records request to WSU, said: "Last month [December], I had a hearing in front of the Utah State Records Committee trying to pry more records from the Utah Department of Agriculture. During that hearing, they made the claim that no serious threat existed to workers or wild animals.

"In fact, at the time they made these claims to the committee, the agency already had evidence that wild mink had tested positive for SARS-CoV-2 and that farm workers had been infected, including a manager on a Utah County mink farm had died of COVID," Beckham said.

During the aforementioned hearing, held on December 8, 2020, the UDAF claimed "that wild transmission has not occurred (and repeated this at a hearing on Dec. 10) to justify the lack of disclosure about mink farm outbreaks," Hsiung told Newsweek.

"Their [UDAF] argument is: We don't need to tell anyone about this because we have it contained. Subsequently, on Dec. 11, it was revealed [in an international public health mailing list published on ProMED] that wild transmission [in wild mink] has occurred—and from testing done sometime from August through October. This shows the state's brief was false. Whether that falsehood was intentional, I cannot say.

"The state of Utah apparently knew about this positive test, yet continued to falsely state that no wild animal transmission had occurred," he said.

Hsiung noted in the Monday DxE blog post: "The release of COVID-19 to the wild was apparently important enough for USDA scientists to warn international disease experts about—making global headlines—but not important enough for Utah to tell its own citizens."

Hsiung also told Newsweek: "Utah also strangely argues in the same filing on Dec. 8 that, while the risk from mink farms is low, the risk from animal rights activists is very high—citing a number of articles about DxE.

"They're on a razor's edge here because, on the one hand, they want to say daily operations at mink farms are not dangerous enough for people to know about but, on the other, dangerous enough that we can't let animal rights advocates know where they are. This is a contradiction. Either mink farms are dangerous or they're not. They can't only be dangerous for animal rights activists, but not for employees or surrounding community members," Hsiung argued.

Speaking to Newsweek, the former chief veterinarian at the USDA's Food Safety and Inspection Service, noted: "If someone is looking for the exact locations of the affected mink farms to be identified, this is rather complicated as this would be under the State jurisdiction and not USDA/APHIS.

"That is because the regulations governing the actions APHIS can take as the federal branch of the government is limited by several factors, including whether or not the disease in causing illness in animals (as APHIS has no authority to address zoonotic infections), whether or not disease has spread outside the state boundaries and if the disease is located within the state borders, have they requested APHIS assistance; etc.

"With no mandatory animal ID laws, APHIS is quite often unable to confirm or share the exact farm location. APHIS has limited staff and relies on the local (state) 'certified' veterinarians to do their trace-backs. That also creates a problem when there is industry pressure on the state not to cooperate," Basu added.
COVID-19 outbreaks at Utah mink farms 'greatly worsened'

Beckham told Newsweek "the problem [COVID-19 outbreaks on Utah mink farms] has greatly worsened since August. We are up to at least 12 mink farms in Utah that have experienced COVID-19 outbreaks, as of early Dec 2020, which is the latest information I have. That's out of 36 farms total in the state. So one-third of Utah mink farms have been hit with COVID outbreaks.

"The latest statement that the Utah Department of Agriculture released is a press statement boasting that COVID-19 cases have been declining on Utah mink farms based on data collected in October and then December," Beckham added.

In a statement released on December 28, 2020, the UDAF stated: "UDOH and CDC began testing mink and other domestic animals on the farms, including dogs, cats and mice. Sampling also included farm workers and a small number of their household contacts. Initial testing showed positive results in mink, dogs, and feral cats on the farms.

"While the results and analysis are still underway for the third round of testing, there is encouraging evidence suggesting that the levels of virus are going down in the mink, cats and dogs living on the farm.

"Additional community sequencing is needed to fully understand the potential for transmission between people and different animal species in this area; however, at this time, based on extensive epidemiologic investigations, there has been no evidence to date of spread from mink to people in Utah," the statement said at the time.

However, Beckham told Newsweek: "This statement neglects to mention why it's impossible to draw any conclusions based on these data points: mink farms begin their 'pelting season' in November, where the overwhelming majority of their animals are killed and skinned, leaving only the breeding stock behind.

"Of course there are fewer COVID cases in mink—there are fewer mink. And the mink that do remain can be spaced in the sheds, making it more difficult for a respiratory virus to be transmitted. Breeding season starts in March and I fully expect to see these numbers rapidly climb again because the underlying problem has not been addressed," he added.

Related Articles

Saturday, July 03, 2021

 #BANFURFARMING
USA
Bipartisan Proposal Would Ban Mink Fur Farms Over COVID, Cruelty Concerns



Twin concerns of cruelty and protection from COVID-19 are behind a new bipartisan proposal in the U.S. House of Representatives that would ban the sale, purchase, import and export of mink
© iStock/Getty A bipartisan proposal would ban mink farming and the selling of mink products in the U.S. in order to stem potential mutations of the COVID-19 virus.

H.R. 4310, proposed by Reps. Rosa DeLauro (D-Conn) and Nancy Mace (R-S.C.), would amend the Lacey Act of Amendments to include mink. The Lacey Act makes it illegal "to import, export, sell, acquire, or purchase fish, wildlife or plants that are taken, possessed, transported, or sold: 1) in violation of U.S. or Indian law, or 2) in interstate or foreign commerce involving any fish, wildlife, or plants taken possessed or sold in violation of State or foreign law."

For example, under the Act, it is illegal to buy wooden products made from trees logged illegally, or to buy products made from endangered animals.

"What we want to do is ban the inhumane practice of farming mink for fur," Mace told The Associated Press on Friday. "At the same time, it's also a public health crisis, so it helps fix both of those situations."

A bipartisan proposal in the U.S. House would ban the farming of mink fur in the United States in an effort to stem possible mutations of the coronavirus, something researchers have said can be accelerated when the virus spreads among animals.

Researchers have said that spread of COVID-19 among animals could speed up the number of mutations in the virus before it potentially jumps back to people.

Last year, the European Centre for Disease Prevention and Control issued new guidance to curb the spread of the coronavirus between minks and humans. The agency warned that when COVID-19 starts spreading on a mink farm, the large numbers of animal infections means "the virus can accumulate mutations more quickly in minks and spread back into the human population."

Denmark reported last year that 12 people had been sickened by a variant of the coronavirus that had distinct genetic changes also seen in mink.

"What we want to do is ban the inhumane practice of farming mink for fur," Mace said Friday during an interview with The Associated Press. "At the same time, it's also a public health crisis, so it helps fix both of those situations."

"Knowing that there are variants, and being someone who cares about the humane treatment of animals, this is sort of a win-win for folks," she added. "And I believe that you'll see Republicans and Democrats on both sides of the aisle work on this together."

According to Fur Commission USA, a nonprofit representing U.S. mink farmers, there are approximately 275 mink farms in 23 states across the United States, producing about 3 million pelts per year. That amounts to an annual value of more than $300 million, according to the commission.

There have been several mink-related coronavirus cases in the U.S. In December, a mink caught outside an Oregon farm tested positive for low-levels of the coronavirus. State officials said they believed the animal had escaped from a small farm already under quarantine because of a coronavirus outbreak among mink and humans.

According to the U.S. Centers for Disease Control and Prevention, a mink on a Michigan farm "and a small number of people" were infected with a coronavirus "that contained mink-related mutations," something officials said suggested that mink-to-human spread may have occurred.

While mink-to-human spread is possible, CDC officials said "there is no evidence that mink are playing a significant role in the spread of SARS-CoV-2 to people."

 Products made from mink fur would be illegal to buy and sell if the bill passes. iStock/Getty

Proposal would ban mink farming to stem coronavirus mutation

By MEG KINNARD

FILE - In this Jan. 4, 2020, file photo Rep. Rosa DeLauro, D-Conn., speaks during a hearing on Capitol Hill in Washington. A bipartisan proposal in the U.S. House would ban the farming of mink fur in the United States in an effort to stem possible mutations of the coronavirus, something researchers have said can be accelerated when the virus spreads among animals. The bill introduced this week is an effort from Reps. Rosa DeLauro, D-Conn., and Nancy Mace, R-S.C. It would prohibit the import, export, transport, sale or purchase of mink in the United States. (Al Drago/Pool Photo via AP, File)


COLUMBIA, S.C. (AP) — A bipartisan proposal in the U.S. House would ban the farming of mink fur in the United States in an effort to stem possible mutations of the coronavirus, something researchers have said can be accelerated when the virus spreads among animals.

The bill introduced this week is an effort from Reps. Rosa DeLauro, D-Conn., and Nancy Mace, R-S.C. It would prohibit the import, export, transport, sale or purchase of mink in the United States.

Researchers have said that spread of COVID-19 among animals could speed up the number of mutations in the virus before it potentially jumps back to people.

Last year, the European Centre for Disease Prevention and Control issued new guidance to curb the spread of the coronavirus between minks and humans. The agency warned that when COVID-19 starts spreading on a mink farm, the large numbers of animal infections means “the virus can accumulate mutations more quickly in minks and spread back into the human population.”

Denmark reported last year that 12 people had been sickened by a variant of the coronavirus that had distinct genetic changes also seen in mink.

“What we want to do is ban the inhumane practice of farming mink for fur,” Mace said Friday during an interview with The Associated Press. “At the same time, it’s also a public health crisis, so it helps fix both of those situations.”

“Knowing that there are variants, and being someone who cares about the humane treatment of animals, this is sort of a win-win for folks,” she added. “And I believe that you’ll see Republicans and Democrats on both sides of the aisle work on this together.”

According to Fur Commission USA, a nonprofit representing U.S. mink farmers, there are approximately 275 mink farms in 23 states across the United States, producing about 3 million pelts per year. That amounts to an annual value of more than $300 million, according to the commission.

There have been several mink-related coronavirus cases in the U.S. In December, a mink caught outside an Oregon farm tested positive for low-levels of the coronavirus. State officials said they believed the animal had escaped from a small farm already under quarantine because of a coronavirus outbreak among mink and humans.

According to the U.S. Centers for Disease Control and Prevention, a mink on a Michigan farm “and a small number of people” were infected with a coronavirus “that contained mink-related mutations,” something officials said suggested that mink-to-human spread may have occurred.

While mink-to-human spread is possible, CDC officials said “there is no evidence that mink are playing a significant role in the spread of SARS-CoV-2 to people.”

___

Meg Kinnard can be reached at http://twitter.com/MegKinnardAP.


Sunday, November 29, 2020

#ENDFURFARMING
Oregon mink farm has COVID-19 outbreak after advocates warned of danger in state














Tracy Loew
Salem Statesman Journal

SALEM, Ore. – An Oregon mink farm has reported an outbreak of COVID-19 among animals and workers.

Oregon Department of Agriculture spokeswoman Andrea Cantu-Schomus declined to say which county the farm is in or how many workers have tested positive, citing federal health privacy rules. The farm has about 12,000 animals, she said.

Outbreaks in farmed mink have been reported in several U.S. states and countries. Earlier this month Denmark announced it would kill all 17 million of the mink raised there after confirmation that 12 people had been infected with a mutated strain of COVID-19 that had spread from mink to humans. That strain has not been found elsewhere.

Oregon has the nation’s fourth-largest farmed mink industry, after Wisconsin, Utah and Michigan. All three of those other states have had outbreaks on mink farms.


The Oregon farmer reported mink with symptoms to ODA on Nov. 19, Cantu-Schomus said.

ODA took samples from 10 of the sick mink, and all came back positive for SARS-CoV-2, the animal virus linked to COVID-19 in humans. Cantu-Schomus was unable to say how many mink were sick, but said the 10 were a sample of the population.

Nov. 25:Dead minks infected with a mutated form of COVID-19 rise from graves after mass culling


Nov. 5:Denmark to slaughter 15M farmed minks over coronavirus fears

On Nov. 23, ODA placed the farm under quarantine, meaning no animals or animal products can leave the farm. 

On the same date, the Oregon Health Authority asked all workers on the farm to self-isolate, Cantu-Schomus said. 

State and national environmental groups have been raising alarm about possible infections Oregon’s mink industry, the Statesman Journal, part of the USA TODAY Network, previously reported.

"This was so foreseeable," said Lori Ann Burd, with the Center for Biological Diversity, one of the groups urging Oregon to take action. "We'll certainly be following up with the agency to demand answers and to find out what they're doing to mitigate this outbreak and public health risk."

In letters to Gov. Kate Brown and state agencies, the groups asked for immediate inspections of Oregon’s mink farms, as well as quarantines and a phased buy-out of the industry.

At that time, state officials said they did not intend to take any of the groups’ recommendations. Oregon's state veterinarian has been communicating with mink farmers about the outbreaks, Cantu-Schomus has said.

“We have been engaged with the Oregon mink industry for some time, providing information on biosecurity to prevent the introduction of SARS-CoV-2 and were ready to respond,” State Veterinarian Ryan Scholz said in a written statement Friday.

“The farmer did the right thing by self-reporting symptoms very early and he is now cooperating with us and the Oregon Health Authority in taking care of his animals and staff,” Scholz said. “So far, we have no reports of mink mortalities linked to the virus but that could change as the virus progresses.”

In Wisconsin, about 3,400 farmed mink have died over the past month after contracting the virus. And in Utah, about 10,000 mink have died since August.

In addition to Denmark and the United States, COVID-19 infections have been reported in farmed mink in the Netherlands, Spain, Sweden, and Italy and Greece, according to the World Health Organization.


All of the mink in the Oregon outbreak appear to have recovered, Cantu-Schomus said. ODA will test the mink 7-10 days after symptoms resolve, and, if necessary, continue testing every 14 days until no more infected mink are found.

The sample size will be significantly larger and will ensure with a 95% confidence level that if the virus was present it would be detected, she said.

"It is suspected that infected workers introduced SARS-CoV-2 to mink on the farm, and the virus then began to spread among the mink," Cantu-Schomus said.

ODA is working with OHA, the Oregon Department of Fish and Wildlife, U.S. Department of Agriculture and the Centers for Disease Control to investigate transmission dynamics among mink, other animals around the farm, and people, she said.

Last week, ODA officials said they had no plans to do inspections or test mink unless symptoms were reported. Cantu-Schomus was unable to say Friday whether that is still the case.

Michael Whelan is executive director of Medford-based Fur Commission USA, a national nonprofit representing mink farmers.

He said the group is offering free COVID-19 testing to farm operators and employees.

"All we can do is just keep reminding the farmers that this is serious and they have to screen all people that get anywhere near the mink," Whelan said.

Cantu-Schomus was unable to say how many farmed mink there are in Oregon.

"There is no evidence that animals, including mink, are playing a significant role in the spread of COVID-19 to people," she said. "Currently in the U.S., there is no evidence of mink-to-human spread. However, investigations are ongoing."

Friday, November 20, 2020

Covid-19 mink variants discovered in humans in seven countries

Denmark has already launched a nationwide cull of its farmed mink herd after concerns for vaccine efficacy

Danish farmers have until midnight on Thursday 19 November to cull all mink in the country. Photograph: Mads Claus Rasmussen/Ritzau Scanpix/AFP/Getty

Animals farmed is supported by
About this content

Sophie Kevany and Tom Carstensen
Wed 18 Nov 2020 

Seven countries are now reporting mink-related Sars-CoV-2 mutations in humans, according to new scientific analysis.

The mutations are identified as Covid-19 mink variants as they have repeatedly been found in mink and now in humans as well.

Uncertainty around the implications of the discovery of a Covid-19 mink variant in humans led Denmark, the world’s largest mink fur producer, to launch a nationwide cull earlier this month.

The cull was sparked by research from Denmark’s public health body, the Statens Serum Institut (SSI), which showed that a mink variant called C5 was harder for antibodies to neutralise and posed a potential threat to vaccine efficacy.

Denmark, the Netherlands, South Africa, Switzerland, the Faroe Islands, Russia and the US have all reported cases of mink-related mutations.


Despite a political backlash the cull has continued, and farmers have until midnight on Thursday to cull all mink in the country. However, the row over the cull has forced the resignation of the Danish agriculture minister, Mogens Jensen.

SSI director KÃ¥re Mølbak has also said he would resign. It was the SSI’s findings on reduced antibody efficacy that led to the cull order. Mølbak told local media he is retiring because he is 65 and denied it was related to the mink cull.

Until now there had been no widespread reports of mink variants in humans outside Denmark. But scientists uploading virus sequencing and variant information to Gisaid, a global database initiative, said there have been signs of the mink variants around the world.

“We knew there were these mink variants in seven countries, but we only had about 20 genomes of each, which is very few. Then last week the Danes uploaded 6,000 genome sequences and with those we were able to identify 300 or more of the mink variant Y453F in viruses having infected humans in Denmark,” said University College London (UCL) Genetics Institute director Francois Balloux.

Asked about the implications of the findings, Balloux said it was an indication of the need to cull farmed mink. “A bigger host reservoir means more infections in humans. The main point here, I think, is that although the mutation might not be scary, there is still very good reason to get rid of the mink reservoir. We just don’t need it.” In Denmark, he added, they have a lot of mink, “over three times more than humans”.


Denmark's mass mink cull illegal, PM admits as opposition mounts
Read more


The prevalence of Danish mink-related mutations is evident in the Gisaid database. “Denmark has 329 F-variant sequences, which roughly maps to as many individuals, although there may be some duplicates,” said Prof Seshadri Vasan, who leads the dangerous pathogens team at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) and analysed the database for the mink variants. “The Netherlands has six. South Africa and Switzerland have two each, while the Faroe Islands, Russia and Utah [US] have one each.”

Asked how the spread might have happened, Vasan said that given some of the human and mink F-variants were from samples collected in Denmark in June, it might be that “movement of people, animals or goods could have spread the F-variant to other countries”.

But, because the Gisaid database includes only patchy patient information and no travel history – and as some of the samples lack collection dates – he said it is impossible to say exactly how and when the spread took place, although local scientists might be better placed to understand.

Last month, Vasan and his team published a global template aimed at improving the collection and sharing of de-identified patient information in a bid to improve data quality.

Viruses are known to mutate, but variants alone are not necessarily a problem. Most importantly, said Prof Joanne Santini, a microbiologist at UCL, we still don’t know whether this mutation happened in mink or humans first.

In a joint email this week to the Guardian, Santini and UCL colleague Prof Sarah Edwards, a bioethicist, said the Sars-CoV-2 Y453F variant in the spike protein is “unlikely to pose any serious risk to the expected efficacy of current candidate vaccines, or itself pose a new public health threat” on its own.

If, however, the variant originated in mink and spread to humans, “then we would have to doubt our ability to manage outbreaks in otherwise seemingly contained farm animals once detected”.

Constant mutations could be a source of concern too. The email added that “multiple additional variants in the spike protein could indeed have concerning implications for how infectious the virus is to humans and also to animals”, potentially posing “new threats to the expected efficacy of our candidate vaccines”.

“The early observations by CSIRO scientists demonstrate the possible implications for the wider spread of Sars-CoV-2 variants between humans and animals,” she said.

Although Denmark is the only country to order a nationwide mink cull, others, including the Netherlands, Spain and, most recently, Greece, are killing mink with Covid-19. On Tuesday, Reuters reported mandatory mink testing had started in Poland, despite industry fears that tests could lead to a nationwide cull.

On the business side, the Danish cull has had immediate effects. Last week, Denmark’s breeder association and world’s largest fur auction house, Kopenhagen Fur, announced a “controlled shutdown” over the next three years, while Danish thinktank estimates put the cost of mink farm closures at about DKK3bn (£360m).

Sunday, November 08, 2020

What's the science behind mink and coronavirus?

Helen Briggs - BBC Environment correspondent,
BBC•November 8, 2020

Mink outbreaks are a "spillover" from the human pandemic

Mutations in coronavirus have triggered culls of all 17 million farmed mink in Denmark.

Part of the country has been put under lockdown after Danish authorities found genetic changes they say might undermine the effectiveness of future Covid-19 vaccines.

More than 200 people have been infected with mink-related coronavirus.

And the UK has imposed an immediate ban on all visitors from Denmark amid concerns about the new strain.

Danish scientists are particularly concerned about one mink-related strain of the virus, found in 12 people, which they say is less sensitive to protective antibodies, raising concerns about vaccine development.

The World Health Organization has said the reports are concerning, but further studies are needed to understand the implications for treatments and vaccines.

"We need to wait and see what the implications are but I don't think we should come to any conclusions about whether this particular mutation is going to impact vaccine efficacy," said chief scientist, Soumya Swaminathan.
Officials arrive at a mink farm to put down the animals

The coronavirus, like all viruses, mutates over time and there is no evidence that any of the mutations found in Denmark pose an increased danger to people.

Dr Marisa Peyre, an epidemiologist from the French research institute Cirad, said the development was "worrying", but we don't yet know the full picture.

"Every time the virus spreads between animals it changes, and if it changes too much from the one that is circulating within humans at the moment, that might mean that any vaccine or treatment that will be produced soon might not work as well as it should do," she explained.

Mink, like their relatives, ferrets, are susceptible to respiratory viruses

This is a very unusual chain of events: a virus that originally came from a wild animal, probably a bat, jumped into humans, possibly via an unknown animal host, sparking a pandemic.

Mink kept in large numbers on mink farms have caught the virus from infected workers. And, in a small number of cases, the virus has "spilled back" from mink to humans, picking up genetic changes on the way.

Mutations in some mink-related strains involve the spike protein of the virus, which is targeted by some vaccines being developed.

"If the mutation is on a specific protein that is being currently targeted by the vaccine developers to trigger an immune response in humans then it means that if this new virus strain comes out of the mink back into the humans, even with vaccination, the humans will start spreading it and the vaccine will not protect," Dr Peyre told BBC News.

More than 50 million mink a year are bred for their fur, mainly in China, Denmark, the Netherlands and Poland. Outbreaks have been reported on fur farms in the Netherlands, Denmark, Spain, Sweden, Italy and the US, and millions of animals have had to be culled.

Millions of mink are being culled in Denmark

Mink, like their close relatives, ferrets, are known to be susceptible to coronavirus, and like humans, they can show a range of symptoms, from no signs of illness at all to severe problems, such as pneumonia.

Scientists suspect the virus spreads in mink farms through infectious droplets, on feed or bedding, or in dust containing droppings.

Mink have caught the virus from humans, but genetic detective work has shown that in a small number of cases the virus seems to have passed the other way, with the virus spreading from mink back to humans.

Mink have become "reservoirs for the virus" and surveillance is required in other wild and domestic animals that may be susceptible, said Prof Joanne Santini of University College London.

"Mink is the extreme but it could be happening out there and we just don't know about it and that's something we need to be checking," she told BBC News.

"What we do know is that the mink are picking up the virus from people; they can be infected and they are spreading it between themselves and it's come back to humans."

Scientists in Denmark are carrying out genetic studies on mink-related strains, and the genetic data has been shared with other researchers, to allow further investigation.

"We need to find out where these mutations are and we need to see what effect that has on transmission of the virus and how infectious it is, because if it is changing and being more infectious or having a broader host range, then that's really quite scary but it might not be, because we don't know," said Prof Santini.

Some scientists have called for new restrictions on mink production, saying mink farming "impedes our response and recovery from the pandemic".

In a recent letter to the journal, Science, three scientists, from Denmark, China and Malaysia, wrote: "It is urgent to monitor, restrict, and - where possible - ban mink production."

The WHO has called on all countries to step up surveillance and tighten biosecurity measures around mink farms.



Saturday, November 06, 2021

 

B.C. to ban mink farms, citing concerns of new COVID-19 variants

Concerns have arisen the virus that causes COVID-19 could mutate in the creatures and spread back to the human population.
mink
A silver mink in a cage. : Photo: Getty Images

B.C. is set to phase out mink farms, citing concerns the virus that causes COVID-19 could mutate in the creatures and spread back to the human population.

To date, three of the nine mink farms across the province have faced outbreaks among animals and farm workers. In July, that led the provincial government to place a moratorium on any new mink farms and cap the expansion of the animals on the farms.

On Friday (Nov. 5), it took one step further and moved to phase out the industry by 2025.

"This decision follows the recommendations of public health officials and infectious disease experts about managing the threat of the virus for workers at the farms and the broader public," said B.C. Agriculture, Food and Fisheries Minister Lana Popham.

BC Mink Producers Association president Joseph Williams told Glacier Media he and the rest of the industry were told their mink farms would be phased out an hour before the province announced the decision.

“Obviously, this is very emotional for us,” he said. “Our livelihoods have just been taken away.”

Williams says his farm in Langley, Williams Fur Farming Ltd., has been in the family since 1991. Today, he runs it with five other family members. Together, Williams, along with the other eight mink farms in the province are now organizing to figure out how they will respond.

“We don’t accept it and we’re looking into what we can do,” he said. “This isn’t based off science. This is an anti-fur agenda.” 

B.C. officials denied that their decision had anything to do with animal rights. Provincial health officer Dr. Bonnie Henry said data from the BC Centre for Disease Control led to concerns the animals would act as a reservoir for the SAR-CoV-2 virus to mutate.

Henry said public health officials have not seen a variant of concern arise in the B.C. mink population, but other viruses have been documented to pass from the animals into humans in other countries.

Last year, both Dutch and Danish authorities culled their countries’ entire farmed mink populations after SAR-CoV-2 was found to have mutated, passing from the animals to humans. 

Since then, there has been a wider push in several countries, including the United States, to ban mink farming.

"Some of those viruses that spread to humans were variants of concern," said Jan Hajek, an infectious disease specialist at Vancouver General Hospital and clinical assistant professor of medicine at UBC.

"It wasn’t such a terrible mutation, but the idea was this could happen."

Mink isn’t the only non-human species that can catch COVID-19. Ferrets and cats — including several tigers and lions at a zoo in New York City — have tested positive; mink, however, present a greater risk to human health, said Henry. 

"The really important factor is the numbers you have in the small space together," she said. "When this virus gets into a population and spreads, replicates in large numbers, that’s when mutations arise."

Those mutations can give an advantage to a virus, as seen with the Delta variant when an explosion of transmission in India allowed the virus to mutate in the human population. 

Public health officials say they’re worried the Delta variant could get passed back and forth between the mink population and even vaccinated people. 

Another concern, said Henry, is that the government has found escaped mink on and close to farms, raising concerns they would pass it to wild species like deer or even cats and dogs.

Throughout the pandemic, Henry said staff from public health, WorkSafeBC and the Ministry of Agriculture have been faced with an "intense amount of work" to inspect, test and ensure biosecurity measures are in place on mink farms.

B.C.’s nine mink farms are home to roughly 318,000 mink and provide jobs to about 200 workers. That includes families that work their own farms and temporary foreign workers employed on a seasonal basis. 

Minister Popham said the decision to eliminate mink farming in the province had nothing to do with ongoing calls from animal rights advocates to ban the practice. 

She said farms will have access to insurance programs and the government will help them to transition to other industries with support provided through its AgriStability program.

Because the mink industry usually kills the animals near the end of the year, both Henry and Popham said mink farmers will be able to sell pelts from all the existing animals. 

The province says it will place a permanent ban on live mink farming by April 2023, with all operations ceasing by 2025. Popham could not provide a number on how much the phase-out would cost.

"We don’t know what [farm owners] are going to want to do with their future, but we’re going to be there along the way," she said.  

Henry added that some mink used for breeding can be kept until 2023, but that they must be sold out of province. That provision has infectious disease expert Hajek concerned. 

"I’d worry they’d just transition to Alberta or move," he said, noting the spread of COVID-19 does not respect provincial or international borders. 

The BC SPCA has called for a ban on mink farms in the province for some time. Despite the province pinning the decision on public health, animal rights activists are hailing the move as a victory. 

"I’m ecstatic," said animal rights lawyer Victoria Shroff. "There’s been pressure on the government to question the industry… This industry has no place in society anymore. 

"I think it’s something we need to follow through for all fur farming in Canada."

Wednesday, November 11, 2020


Dutch scientists reconstruct spread of coronavirus through mink farms

So far, however, no evidence of dangerous mutations being selected in mink.


JOHN TIMMER - 11/10/2020


It's still not clear what species carried the SARS-CoV-2 coronavirus that made its way into humans. But it has become increasingly clear that we can spread it to a large number of species, and a subset of those species are then able to pass it on to others. If those species are able to pass it back to humans, it adds to the risk posed by the COVID-19 pandemic. That's because it provides a route for new infections that avoids all of the means we're using to try to control the virus's spread between humans. And there's also the chance that the virus's reproduction within an animal species would select for a mutation that would make the virus more dangerous to humans.

While we've already found the virus in cats and dogs, the big risk so far has turned out to be an unexpected source: mink. As early as August, it was clear that the virus was killing lots of the animals on US mink farms. Earlier this month, the discovery that the virus had spread back from mink to humans caused Denmark to decide to cull its entire population of mink. Now, with some people on edge because of that drastic action, we have a report that provides detailed tracing of the virus' spread between mink and humans, providing us a better sense of the risks involved.


FURTHER READING


There and back again

The work was done in the Netherlands, which also hosts a substantial number of mink farms. The new paper, written by public health and veterinary officials, is essentially the equivalent of a contact-tracing report done for mink. It uses a combination of diagnostics to identify people and animals that have been exposed to the SARS-CoV-2, whole genome sequencing to understand the source of those infections, and interviews (limited to the humans) to help determine any actions that might influence the virus's spread.

Overall, the researchers were able to trace infections on 16 different farms, although in at least one case, two farms had the same owner and shared workers. The researchers were also able to compare the genomes of the viruses found on those farms to a panel of over 1,700 viral genomes found in the general population of the Netherlands.

The first thing that is very clear from the survey: the virus is widespread among the farm workers. Of the roughly 100 people tested, 68 percent were either currently infected or had antibodies indicative of a past infection. A number of people were either known to have had a case of COVID-19 or reported having had respiratory symptoms during the interviews.

Samples were obtained from the people with active infections, and the entire genome was sequenced, allowing the researchers to reconstruct its evolutionary history. In each of these cases, the farm workers were carrying a virus that was most closely related to the strains known to be circulating in mink. This indicates that these workers were picking up SARS-CoV-2 from the animals in their care. Separately, it was clear that many of the farms had distinct infections, which suggested that the virus had spread from humans to mink multiple times.
Staying on the farm

That's the bad news. The good news is that it doesn't appear to be spreading much from farm workers to the general population. The researchers identified 34 infected people from the same post codes as the mink farms and sequenced the genomes of their viruses, too. In all cases, those viruses looked like the ones that were in general circulation among the Netherlands' human population rather than the ones common on the mink farm. In only one case did one of the workers spread a mink SARS-CoV-2 strain to someone they spent time with.

(Many of the mink-farm workers in the Netherlands are from Poland, but viruses circulating in that country were even more distantly related.)

Does the virus seem to be adapting to mink in any specific ways? Not obviously, according to the sequences available. The 16 farms grouped into five distinct clusters of related viruses, and they don't seem to have much in the way of common mutations, as you might expect for a virus adapting to a new species. And for the most part, the viruses that hopped back into humans from the mink simply looked like variants on the ones from the mink.

The only thing that might suggest some added risk of having the virus in mink is that it seems to pick up mutations with the animal at a somewhat faster rate than it does within humans. But because of the large uncertainties about when the infections in the mink farm started, that's going to require considerably more data before we can say anything with confidence.
Hooray?

So overall, the news is somewhat reassuring. While it's clear that the mink can give us back the virus we gave them, it hasn't led to widespread infections in the communities around the mink farms. It's obviously worth trying to figure out whether the workers took any precautions that helped limit the spread of their infections—something the interview material gathered by the researchers can undoubtedly address.

The other good news is that the virus doesn't seem to have accumulated any mutations that clearly help it adapt to that species. That can clearly change with time, so we'll want to continue monitoring these farms. But in the absence of that, the presence of the virus in mink doesn't seem to pose a dramatic threat to humans. Obviously, we'll want to look out for any data gathered in Denmark or other countries with large mink farms to see if the data is consistent with this. But if it is, it will be very reassuring.

Science, 2020. DOI: 10.1126/science.abe5901 (About DOIs).

Sunday, October 11, 2020

At least 12,000 mink dead as coronavirus spreads among fur farms in Utah and Wisconsin

Harriet Alexander, The Independent•October 9, 2020





Thousands of mink bred in fur farms in Utah and Wisconsin have now died form Covid-19 (AP)

Thousands of mink bred in fur farms in Utah and Wisconsin have died from coronavirus, after scientists believe the virus was introduced to the animals by humans.

The outbreak was first noticed in Utah in August. Ten thousand mink have now died in Utah fur farms, a spokesperson from the Utah Department of Agriculture and Food (UDAF) told CBS News on Friday.

This week Wisconsin, the largest fur-producing state, became the second state to confirm a Covid-19 outbreak among their mink population, with one farm affected so far.

Two thousand mink in the one farm - which is now under quarantine - have died, the channel reported.


Wisconsin’s Department of Agriculture, Trade and Consumer Protection (DATCP) said that it had implemented new measures for "carcass disposal, cleaning and disinfecting the animal areas, and protecting human and animal health."

On Wednesday a third state, Michigan, confirmed that mink there had tested positive too.
Wisconsin has the largest mink fur farming industry in the United States
Professor Tim Blackburn / UCL

Scientists believe that humans passed the virus to the animals, and not the other way round.

This week researchers from University College London (UCL) concluded that 26 animals, including farm animals like pigs, horses and sheep, may be vulnerable to infection with coronavirus and could “warrant further investigation and possible monitoring”.

Professor Christine Orengo, from UCL Structural and Molecular Biology and lead author of the study, said: “We wanted to look beyond just the animals that had been studied experimentally, to see which animals might be at risk of infection, and would warrant further investigation and possible monitoring.

“The animals we identified may be at risk of outbreaks that could threaten endangered species or harm the livelihood of farmers.”

She pointed towards cases of coronavirus outbreaks in mink farms that show some animals may act as “reservoirs” of Covid-19, with the potential to re-infect humans.

The scale of the outbreak among mink is unclear, as the fur farms say it is impossible to test every single animal.

The Fur Commission USA, which represents mink farmers, say that there are approximately 275 mink farms in 23 states across the county, producing about three million pelts annually, with a value of more than $300m.

Fur from the dead, infected mink is still being used commercially, and Fur Commission USA told the AP that the fur is processed to eliminate all traces of the virus before it is used for clothing.

As with humans, younger mink are less likely to contract the virus, and most deaths occur among older mink, ages one to four years old.

Difficulty breathing is a common symptom, but the virus progresses extremely quickly, killing most infected mink by the next day.

Researchers have reported that mink are especially susceptible to the virus due to a specific protein in their lungs.

The Netherlands has now moved up its deadline to end mink fur farming by three years to prevent future outbreaks, and killed thousands of animals earlier this year to stop the spread. Spain followed a similar path, and last week Denmark announced a million mink will be killed to stop the outbreak among animals there.

The Humane Society of the United States has called the inaction by the US government "indefensible."

"Fur farms are miserable places for wild animals like mink," Kitty Block, president and CEO of the Humane Society of the US.

"Now, with the coronavirus outbreak killing the animals by the thousands, the suffering has only intensified.

"The only way to end the dual problems of pandemic outbreaks on fur farms and the animal suffering inherent in fur farming is to close down this industry for good."

Read more

Scientists test whether coronavirus can be passed from minks to humans

‘Considerable risk’ of humans transmitting Covid-19 to wild animals

Calls to shut down fur trade after mink become infected with Covid-19

Friday, December 25, 2020

Mink on second B.C. farm test positive for COVID-19

Health officials have detected COVID-19 at a second mink farm in B.C.'s Fraser Valley.
© HENNING BAGGER/Ritzau Scanpix/AFP via Getty Images In this file photo, minks are seen at a farm in Gjol, northern Denmark on October 9, 2020.

In a media Christmas Eve media release, the Ministry of Agriculture, Food and Fisheries said three mink had died at a second farm in the province.

Subsequent testing revealed the presence of SARS-CoV-2, the virus that causes COVID-19 in humans. No workers have tested positive so far.

The farm has been put under quarantine preventing the movement of animal or materials from the property, the ministry said.

The mink were tested after some animals at the farm experienced diarrhea, the ministry said. Twenty-three of the farm's 1,000 animals have died between Dec. 19 and Dec. 23.

COVID-19: hundreds of mink die at Fraser Valley farm


It remains unclear how the mink contracted the virus. The farm is not being identified.

No worrying COVID-19 mutations at B.C. mink farm, say health officials

Health officials said Wednesday that genetic sequencing has found no worrying mutations in samples of COVID-19 taken at the first B.C. farm to have an outbreak of the virus.

At least 17 workers and their contacts and five mink at the farm, which has not been publicly identified, have tested positive for the virus. Another 200 mink died at the site earlier in December.

Video: Fraser Valley mink farm COVID-19 outbreak raises concern about virus mutation

The B.C. Centre for Disease Control said samples of the virus were examined by both its own Public Health Laboratory, and the Canadian Food Inspection Agency's National Centre for Foreign Animal Disease Laboratory in Winnipeg.

"One common mutation was detected in both the animals and the farm workers," said the BCCDC.

Read more: Hundreds of mink dead from COVID-19 on Fraser Valley farm in B.C.

"This mutation is not in the spike protein of the coronavirus and has been reported in mink previously. Neither the mutation nor the outbreak present an increased risk to human health at this time."

The tests also revealed that the workers and the mink were infected with an "identical or nearly identical" strain of the virus, which has been circulating in B.C.

The BCCDC said that indicates the virus spread from people to the mink, not the other way around.

The agency said further human testing was underway, and that more samples would also be collected from mink.

Read more: Containing COVID-19 outbreak to single B.C. mink farm essential, say experts

The outbreak at the farm has been contained, the BCCDC said, adding that public health and the Ministry of Agriculture, Food and Fisheries continue to monitor mink farms.

The outbreak was the first in Canada on a mink farm, but followed multiple outbreaks in Europe and the U.S.

Mutation concerns rise over COVID-19 outbreak at B.C. mink farm


In Denmark, scientists discovered that the virus had been contracted by mink, mutated, then spread back to humans -- raising concerns it could affect the efficacy of a COVID-19 vaccine.

The country subsequently culled 17 million of the animals.

Research has since found the Danish mutations were less worrisome than originally thought, but could potentially affect how well antibody therapies work on the virus, according to Dr. Jan Hajek, a UBC infectious disease specialist.

Thursday, July 06, 2023

American mink regrow their brains in a rare reversal of the domestication process

New research by the Max Planck Institute of Animal Behavior (MPI-AB) suggests that loss of brain size is not permanent in domesticated animals

Peer-Reviewed Publication

MAX-PLANCK-GESELLSCHAFT

American mink 

IMAGE: NATIVE TO NORTH AMERICA, THE AMERICAN MINK HAS BECOME FERAL THROUGHOUT EUROPE. view more 

CREDIT: KAROL ZUB




Farm animals look different from their wild counterparts in many ways, and one difference is consistent: their brains are smaller than those of their ancestors. From sheep to pigs to cows, domesticated animals have smaller relative brain sizes compared to their wild counterparts—a phenomenon known as the domestication effect. Now, a study by the Max Planck Institute of Animal Behavior (MPI-AB) has discovered a rare reversal of the domestication effect. Over the course of captive breeding, the American mink has undergone a reduction in relative brain size, but populations that escaped from captivity were able to regain almost the full ancestral brain size within 50 generations. The study is published today in the Royal Society Open Science.

“Our results show that loss of brain size is not permanent in domesticated animals,” says Ann-Kathrin Pohle, a Master’s student at MPI-AB and first author on the paper. “This finding deepens our understanding of how domestication has changed the brains of animals, and how these changes might be affecting animals when they return to the wild.”

Understanding the feral brain

When animals lose brain size through the course of domestication, it’s mostly considered to be a one-way street. Animals almost never seem to regain the relative brain sizes of their ancestral forms, even in feral populations that have been living in the wild for generations. “Once animals loose parts of their body, such as certain brain regions, over the course of evolution, they are gone and cannot simply be regained,” says Dina Dechmann, senior author on the paper, and a group leader at MPI-AB.

Studying whether or not feral animals can regain the relative brain sizes of their wild counterparts is also difficult methodologically. To properly do so, Dechmann says, “you would need to find an animal with separate wild and feral populations to reduce the chance that the groups had mixed. And, you would need to find an animal that could be studied through sufficient brain and skull measurements.” You would need an animal, in other words, like the American mink.

Native to North America, the American mink has been domesticated for the fur trade for over a century. After they were bred in Europe for fur farming, captive animals escaped to form feral populations that have spread throughout Europe. This natural history thus provided the separated populations that Dechmann and her team needed: wild mink from North America, domesticated mink from European fur farms, and feral mink from Europe.

To explore changes in brain size, the team turned to a proxy: skulls. “Braincase size is a good proxy for brain size in mink, and this allows us to take measurements from existing skull collections without the need for living animals,” says Pohle. A museum collection from Cornell University was used to study skulls of wild American mink while European fur farms provided skulls of domesticated animals. For the feral population, Dechmann  and Pohl collaborated with Andrzej Zalewski at the Polish Mammal Research Centre who had a collection of skulls obtained from an eradication program of feral mink. “Usually, the difficulty with skull studies is finding big enough collections to work with,” says Dechmann. “We were incredibly fortunate to work with multiple organizations to obtain the population samples we needed.”

The team took measurements from skulls to calculate relative brain size of the animals. They found that, according to the well-documented domestication process, the brains of captive-bred mink had shrunk by 25% compared to their wild ancestors. But, in contrast to expectations, the brains of feral mink grew almost back to wild size within 50 generations.

Flexible brains

Dechmann suspects she knows why this animal, in particular, has achieved what was thought to be unlikely. American mink belong to a family of small mammals with a remarkable ability to seasonally change their brain size in a process known as Dehnel’s phenomenon. Dechmann, an expert on this process, has documented Dehnel’s in shrews, moles, and weasels.

“While other domesticated animals seem to lose brain size permanently, it’s possible that mink can regain their ancestral brain sizes because they have flexible brain size built into their system,” she says.

This flexibility could have offered advantages to the mink that re-entered the wild. “If you escape from captivity back to nature, you would want a fully capable brain to navigate the challenges of living in the wild. Animals with flexible brains, like the mink, could restore their brains even if they had shrunk it during an earlier time.”

The results don’t reveal if the brains of feral mink function the same as wild type mink. To find that out, the team would have to examine the brains of animals, which is a step for a future study.