Ferrets and COVID-19: What You Need to Know
By Dr. Chris Vanderhoof
Viruses can be frightening. We can’t see them, we can’t smell them. And yet, they cause some of the worst diseases the world has ever seen, including Ebola virus disease, rabies, distemper, parvovirus, HIV, yellow fever, and influenza. As you likely know, the global outbreak of COVID-19 is caused by a virus too.
This is why a lot of panic and fear surrounds a new viral outbreak. It’s tough to know where a new virus came from and it’s not always understood how people get infected.
Many people understand that viruses can be host-specific. Some viruses only infect people, and some only infect certain other animal species.
But many also know that some viruses can pass between animals and people. This leads to significant concerns among most pet parents. Can I get this disease from my cat? How about my dog, my horse, or my ferret?
Many ferret parents read a lot of news about their adorable mustelid friends, so it’s not surprising that they are concerned now. Some preliminary research started coming out that said ferrets were being considered as the top model for studying COVID-19.
These concerns are shared throughout the animal care world. Dogs and cats have been relinquished and even abandoned by their owners over fears that their pets might be a source to infect them with COVID-19.
But dogs and cats aren’t being utilized as models for research, and ferrets are. So what does that mean, both for ferrets in a laboratory setting and for pet ferrets at home?
In this in-depth article, we’re going to answer a number of questions you might have, including:
- Why are ferrets currently considered a top model for COVID-19 research?
- What’s going on with ferret research? Is COVID-19 the same in ferrets as in people?
- Are ferrets in research able to pass the virus to healthy ferrets? Can they infect people?
- How are the ferrets themselves being treated? Has the escalation around this virus and demand for a vaccine relaxed ethical treatment guidelines?
We’ll go through each of these complex questions, and more.
But before we really get into COVID-19 details, it’s important to explain what a virus is.
What’s a Virus?
A virus is composed of genetic material, like DNA or RNA, wrapped up in a protein shell called a capsid. There is a lot of variety to viruses, whether composed of DNA or RNA, and whether they have just a single strand of genetic material, or two strands. Some viruses also have an outer protective layer called an envelope that surround their capsid.1
Viruses can’t reproduce on their own. All viruses require a host in order to make more of themselves. They infect a host’s cells and hijack the replication machinery to cause and spread disease.
How Do Viruses Infect People?
A virus may not be considered “alive”, in the traditional sense, but that doesn’t make it inert. A virus is still composed of genetic material, which is arguably the most powerful force in the natural world.
A virus is unwittingly introduced by the host itself in most cases, usually through ingestion or inhalation. Viruses have different abilities to resist environmental factors, enabling them to survive on different surfaces before they decompose. Without disinfection, some can remain viable for weeks, while others lose their ability to infect a living thing after only a few hours.
We’re not talking about just a single virus particle either. If someone sneezes flu virus all over a table, it will be covered in virus particles. If someone comes along, touches the surface, and then rubs their eyes or nose, they can expose themselves to thousands of virus particles.
Once introduced to the host, the virus can circulate through the body, latching onto cells to infect.
All cells have a variety of receptors on their surfaces. These receptors are needed for all kinds of normal processes. A virus has the ability, based on its genetic code, to bind to a particular receptor for a certain cell. The cell doesn’t know it’s a virus attaching, just that it has the correct receptor.
This is kind of like having the right key for a lock. If someone in your household lost a key to your house outside and a stranger picked it up, and started to unlock your door, you might just assume it’s a family member. Why would anyone else have your key, right? This is similar to what happens in the body when a virus attaches to a cell.
But once a virus gets inside a cell, it takes over that cell’s machinery to make more of itself.
As more and more viruses get produced inside the cell, the cell’s capacity to hold them reaches a breaking point, and the cell literally bursts open, allowing the new viruses to seek out more cells and repeat the cycle.
How Can a Virus Infect Both Animals and People?
There are over 200 human viruses that have been discovered, with a few additional ones being added every year. The first human virus discovered was the yellow fever virus. Though the disease yellow fever was documented as early as the 17th century, it wasn’t identified as a virus until 1901.
More than two-thirds of viruses that affect people, can also affect animals, including mostly mammals but also birds. But even some exclusively human viruses have been found to have their origins in other animal species.
A substantial portion of viruses can cross the species barrier from animals into people, but fortunately, many of these viruses are incapable of causing widespread disease and outbreaks.
But still, how exactly is this cross-species transmission possible? At the most basic level, this comes down to cell receptors. People and animals share many similarities at the molecular level. One of those similarities is that we can have some of the very same receptors on our cells. So while you might look very different from your furry friend, some aspects of your cell structure are the same.
And now, with some of that basic understanding, let’s get into what most of you all reading out there really want to know more about: how do ferrets factor into all of this?
To understand how and why ferrets are important for research on COVID-19, it’s important to know a little history about how ferrets have been involved with research for other respiratory viruses.
Ferrets and Influenza
Ferrets have been research models for influenza viruses since the 1930s. In fact, influenza A, the most common variant of human flu (the 1918 “Spanish flu” pandemic was caused by an influenza A virus), couldn’t be fully studied until nasal samples from infected humans were transferred to ferrets and they were found to exhibit nearly identical symptoms.
Most studies attribute this similarity to a cell receptor common to humans and ferrets called SA𝛼2,6Gal (the “SA” is short for sialic acid, and the “Gal” for galactose). Both humans and ferrets have the same distribution of this receptor in their respiratory tracts. In 2014, researchers found another common receptor called Neuraminidase 5Ac (Neu5Ac) that we share with our mustelid friends, which is not seen in some other animal species.
If you’re saying, “well that’s flu and this is coronavirus”, you’re right. Influenza viruses and coronaviruses are not the same thing and they do use different receptors. But influenza and coronavirus cause similar respiratory diseases in people, and ferrets were already considered to be good models for influenza, so ferrets were immediately considered as a model for coronavirus.
Ferrets and SARS
Ferrets were first utilized for coronavirus research over ten years ago during the severe acute respiratory syndrome (SARS) outbreak in 2002-2003 caused by the coronavirus SARS-CoV-1.
But before we talk about the coronaviruses more, let’s establish some terminology. The proper name for the current novel coronavirus is severe acute respiratory syndrome coronavirus 2, SARS-CoV-2 for short. You might still see some people using the term 2019-nCoV (nCoV referring to “novel coronavirus”). COVID-19 is more specifically the term for the disease SARS-CoV-2 causes. For simplicity, we’ll refer to SARS-CoV-1 as just the “SARS virus” and the current coronavirus as the “COVID-19 virus”.
SARS virus affects the respiratory tract, causing severe pneumonia, and has continued to be studied ever since the outbreak. This research answered several key questions about the SARS virus, thanks in large part to the involvement of our ferret friends as models.
One important discovery is related to the receptor that the SARS virus uses. Researchers found that it uses the angiotensin converting enzyme-2 (ACE2) as the “lock”, for which the virus has the “key” to enter cells. Researchers have found that this enzyme plays the same role for the COVID-19 virus as well.
Some may be familiar with ACE, since ACE inhibitors are a common medication type for human patients with hypertension and heart disease. One reason the SARS and COVID-19 viruses lead to such severe respiratory disease, is that ACE2 is found readily on alveolar epithelial cells in the lungs.
As a brief aside, some readers on ACE inhibitors may be wondering if they have any increased risk from being on their medication. ACE inhibitors have little direct effect on ACE2. Early reports that ACE inhibitors may lead to increased levels of ACE2 and thereby may worsen COVID-19 infections are unsubstantiated and most medical specialty groups are recommending folks stay on their ACE inhibitors. Many people who have died from COVID-19 have had concurrent heart disease and hypertension, and ACE inhibitors may have more of a protective effect to reduce heart and blood pressure complications for folks with the disease
Another important discovery is that while ferrets were found to share this ACE2 enzyme as a receptor for SARS, and virus could be isolated from their lung tissue, they didn’t develop the same kind of severe pneumonia that human SARS patients developed. In fact, no other animal did. Just us.
Fortunately for everyone, although the SARS virus infected nearly 8000 people and killed just under 800 of us, it petered out after a few months and did not lead to the large-scale pandemic that was feared.
Ferrets and MERS
The next coronavirus that emerged was the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. This one was thought to have originated in bats, which was also the case with the SARS virus and is also suspected for the COVID-19 virus. The only other animal species it was found to infect other than humans were dromedary (one-humped) camels. While there were theories the virus could infect cows, sheep, and goats, none of these animal species showed signs of disease.
Scientists identified the receptor MERS-CoV uses to gain entry into cells as dipeptidyl peptidase 4 (DPP4), which is different from the receptor used by the SARS and COVID-19 viruses. They found that while the presence of this receptor in humans led to reproduction of the virus, hamsters, mice, and ferrets did not get disease despite having the same receptor on their cells.
Fortunately, MERS has enjoyed only a brief and limited outbreak potential. About 2500 people have been confirmed with it since 2012, with about 860 deaths, according to the World Health Organization.
Ferrets and the Novel Coronavirus
And now, this gets us to the current viral pandemic crisis with the COVID-19 coronavirus.
As you can imagine, research has been fast and furious on this virus given the severity of the outbreak.
To provide some of the best, most updated information for ferret parents out there, I contacted Dr. Darryl Falzarano, a lead researcher with the Vaccine and Infectious Disease Organization- International Vaccine Centre (VIDO-InterVac) with the University of Saskatchewan in Saskatoon, Canada. His work focuses on the development of animal models and vaccines for emerging viruses, with previous work on Ebola and MERS-CoV.
His team has been tasked, along with several other labs around the world, to work on development of a vaccine for the COVID-19 virus. He has worked with ferrets extensively in a laboratory setting and was generous to provide some of his valuable time to answer some questions specifically for this article.
How Are Ferrets Used as a Model for COVID-19 Research?
When asked about the pros and cons of using ferrets as a model for COVID-19 research, Dr. Falzarano referred to their previous use as models for influenza, for which they are “great models” and for SARS, for which they are “reasonably good” models.
He said that for COVID-19, ferrets are proving to be about as good a model as they were for SARS. They carry the ACE2 receptor, which he confirmed is the main way the COVID-19 virus enters cells. Ferrets can be infected with the virus, they can shed the virus, and on the microscopic level, their tissues show some of the same changes as in humans.
But where they do fall short as models for people is in the types of symptoms they show, which appear to be scarce from his team’s observations. “We’re only seeing really mild disease that varies from group to group.” says Dr. Falzarano. “They’re a little slower for a couple of days, with maybe some ruffled fur, but that’s it.”
When asked if this behavior was in any way related to fever, he said that there have been no temperature changes in their ferrets. And in fact, the slower behavior appears to occur after the peak of viral shedding, so it’s unlikely directly related to virus effects.
“These signs are probably more related to the immune system responding to the virus.” he said. This could be compared to how any of us or our pets feel after receiving a vaccine, which can often cause a mild lethargy for a day or two as our immune systems do what they’re supposed to do to create antibodies.
As for being models for COVID-19, Dr. Falzarano said that ferrets do not mimic exactly the signs of disease seen in people, but they are still very useful for evaluating antivirals and vaccines, because they still carry and shed virus.
Ferrets in the Lab Setting
As an animal lover myself, I wanted to make sure to ask Dr. Falzarano about the ethical treatment of ferrets in laboratories during this outbreak amid the rush to discover therapies.
For those out there not aware, laboratory animal use in North America is highly regulated and scrutinized, with an extensive approval process to ensure that all steps being taken and procedures being performed are vital to the research process and that no animals are treated inhumanely.
A well-balanced animal care and use committee typically consists of a veterinarian experienced in laboratory animal research, a practicing scientist experienced with animal research, a non-scientific member (like an ethicist or animal welfare lawyer), and someone who is not affiliated with the research institution, like a member of the local community. It may also include technical staff and students as appropriate.
Because the current crisis has truly accelerated research efforts on coronavirus, some folks out there may be worried that animal treatment and ethics would fall to the wayside.
But Dr. Falzarano assured me this was not the case. “The only thing that has changed,” he said, “is how long the approval process takes. That process normally takes a longer time with submitting protocols.” He went on to elaborate that the approval process for new research can take 3 weeks or longer. But now, the lab is operating under an emergency evaluation procedure, giving any research with COVID-19 priority. This process now only takes 1-2 days.
Other than that, all animal care and use guidelines and ethical standards are the same. “There have been no changes, we’re following the exact same process we normally follow.” he said.
Ferrets on the Home Front
Ferret parents all over the world are wondering what this research means for their own personal furry pals. When lab findings come out, it can be hard to understand and interpret what these findings mean for the average ferret and their human at home.
As recently as March 30, a pre-published study from the Harbin Veterinary Research Institute was released that looked specifically at several domestic animal species including dogs, cats, ferrets, pigs, chickens, and ducks and whether or not they could become infected with COVID-19. They also explored whether they could pose a health risk to people.
While dogs were found to exhibit some virus reproduction, none of the virus material isolated from dogs was infective, and no dogs showed clinical signs of disease. This matches reports from the two dogs in Hong Kong in who virus was detected, but who never showed signs of disease.
The pigs, chickens, and ducks simply couldn’t be infected at all.
Cats and ferrets were shown to efficiently allow the virus to reproduce in passages of the upper airway. But the good news for our pets is that none of the animals in the study developed serious signs of disease or pneumonia and none of them died of the disease.
Ferrets tested on day 2 of infection showed virus only in the nose and back of the throat area. On day 8, it was found in the nose, back of the throat, tonsils, and trachea (the airway leading to the lungs). By day 14, there was no virus detected at all.
Experimentally-infected cats were shown to be able to transmit the virus to healthy cats, but no transmission study was conducted with ferrets. But still, if cats can pass it to each other, why not ferrets?
I questioned Dr. Falzarano on this newer information to see how it correlates with what his team has seen in ferrets and what types of inferences could be made.
He said that while his own lab has not evaluated ferret to ferret transmission, there is one study that has shown that experimentally-infected ferrets can infect an otherwise healthy or “naive” ferret.
This study, approved for publication in Cell Host & Microbe and released at the end of March, exposed a small group of ferrets to high levels of virus. A second group of ferrets, which had not been exposed, were placed in direct contact with the exposed ferrets, while a third group of ferrets were placed in close proximity, defined as an “indirect contact” group.
The infected ferrets reportedly did show signs of fever and mild coughing, as did the direct contact group, but the indirect contact group did not develop any visible symptoms. This suggested that an infected ferret could transmit the virus to another in close contact.
The implications here could be understandably concerning to many, and they have already caused some panic among cat and ferret owners.
But there’s one very important point you have to factor in, as not only Dr. Falzarano points out, but many other veterinary and public health experts have as well.
Experimental infection is very different from natural transmission.
First, the levels, or number of virus particles used in a lab setting is likely much higher than what a human being probably expels. Dr. Falzarano gives an example from their own research to illustrate how virus levels can affect ferrets differently.
When introducing the virus to ferrets, researchers at VIDO-InterVac used two different levels of virus particles. “We used the highest dose we could do in a reasonable way, and then a 3 logs lower dose.” he said. This equates to about a 99.9% reduction in the amount of virus used.
The ferrets with the high dose were productively infected and able to shed the virus. But the ferrets with the lower dose developed no productive infection or viral shedding at all. Dr. Falzarano believes these ferrets were still technically infected, but not in a meaningful way, where they could transmit an infection.
The dose amount of virus appears to make a significant difference in experimental infections, and may be the reason why ferrets in one study showed some mild signs of illness, while ferrets in other research studies have not. We also have to consider that many of these studies use a very small number of animals–in some cases groups of only two–and there is a risk to overinterpreting these results.
Lab ferrets are exposed to such a high level of virus, because you have to be able to prove as a researcher that any vaccine or antiviral can still perform at that high a level. “Experimental infection is not mimicking natural infection,” Dr. Falzarano said. “And this is why it’s a model.”
Additional Research on Pets and the Novel Coronavirus
This same concept was echoed by virologist Linda Saif with the Ohio State University in Wooster, who was interviewed for an article in Nature on April 1. In response to concerns about cats transmitting the virus to each other in a lab setting, Dr. Saif states that the results are based on lab experiments in which a small number of animals are deliberately given high doses of the virus and do not represent real-life interactions between people and their pets.
Dr. Saif also points out in the article that in previous studies of the SARS virus, cats were also shown to get infected and pass it on to other cats in a lab setting, but there was never any indication during that outbreak that SARS became widespread in housecats or that the virus could be transmitted from housecats to people.
Dr. Michael Lappin, a veterinary professor of infectious disease at Colorado State University and chair of the World Small Animal Veterinary Association (WSAVA) One Health Committee also supports this point during a webinar on April 3 updating veterinarians and other animal care professionals on the most recent guidelines and recommendations.
“I do want to remind you, especially those of you not in the veterinary field, that these experimental infections, while with the same virus, are very high dose experimental infections generally, and we don’t know for sure how well they correlate to the dose of virus that a person with COVID-19 might share with their particular companion animal.” said Dr. Lappin.
It stands to reason this would be the same with ferrets, and experts seem to feel that’s the case. While the small number of ferrets in one study did appear to show some mild signs, many other ferrets exposed to high levels of virus have not, and most virus being shed naturally by people is likely to be even lower than that.
But let’s say that a ferret was infected, for how long does he or she harbor the virus and more importantly, could a ferret shed virus into the environment?
In experimentally-infected ferrets in his own lab, Dr. Falzarano shared that they were only seen to shed infectious levels of virus in nasal washes for 3-4 days. This is similar to the ferret transmission study, which states viral shedding peaks at around 4 days and is gone by 6 days.
And while testing by polymerase chain reaction (PCR) may still detect viral RNA for as long as 10-12 days, Dr. Falzarano indicated that PCR testing is considerably more sensitive than infectious virus assays. PCR also identifies only genetic material rather than live, infectious virus. So essentially, while reports that ferrets may test positive for the virus for up to two weeks is technically accurate, they likely stop shedding infectious virus long before that.
So, can a ferret transmit the COVID-19 virus to a person?
In Dr. Falzarano’s opinion, no. “Could an experimentally-infected ferret transmit? Probably. But this isn’t a normal, everyday situation.” He points out that an average ferret living at home is not going to be exposed to even close to the amount of virus particles that they introduce ferrets to in the lab.
But what about a person giving COVID-19 to a ferret?
According to Dr. Falzarano, there has been no established level of how many virus particles a human expels, at least not yet. If we assumed a human expels a higher number, then a human could transmit to a ferret in theory, but likely only if they were symptomatic, or on the verge of being so, when viral shedding is highest.
But what about asymptomatic people? Reports have been coming in for weeks that asymptomatic people can probably transmit the virus before they show signs of illness, which is how the virus has spread so widely.
While the most recent data does, indeed, support this, it also shows that the amount of virus an asymptomatic person can transmit appears to be low. It’s not zero, but it is much lower than the amount of virus spread by someone with symptoms.
In the WSAVA webinar, Dr. Lappin shared data from the Diamond Princess cruise ship out of Yokohama Japan, where researchers determined that of the people who had COVID-19, only about 18% were asymptomatic, and most of these folks were shedding very low levels of virus.
Dr. Lappin also shared some data showing that if you are infected with COVID-19, you’re going to be shedding the most virus starting the day before symptoms develop and for the first few days you show signs of illness.
And lastly, in terms of transmission potential, Dr. Lappin referenced a study out of Singapore looking at 3 transmission clusters of COVID-19 which found that only 2 of 425 close contacts of confirmed infected individuals developed COVID-19, meaning that most cases identified in the clusters did not transmit to their close contacts.
This is where the benefits of social distancing, especially around anyone who is symptomatic, are really highlighted. If only a few spreading events occur in dense clusters of people, keeping our distance from others can make a big impact.
For you and your ferret, this means that it’s extremely unlikely you will transmit the virus to your pet. If you’re asymptomatic, the risk of infecting your ferret is very low, as is the chance that your ferret could pass the virus on to someone else.
Dr. Falzarano points out that ferrets aren’t acting as amplifiers for the virus either. The ferrets exposed to the lower level of virus in the lab didn’t shed any infectious virus. So if a ferret was exposed to an asymptomatic person, it’s not like the ferret could become a greater risk to others than the asymptomatic person themselves.
Dr. Falzarano believes that, based on what we know so far, ferrets are unlikely to be major contributors of zoonotic risk to people.
This means that even if a person did transmit virus to a ferret in their home, the levels would likely be so low that that same ferret could not truly act as a source of infection for another person.
Dr. Lappin concluded by stating that “while experimental infection has now been confirmed in several companion animal species, there’s still been no social media, experimental, and/or natural evidence that a pet that was living with a person with COVID-19, and exposed to SARS-CoV-2 virus, that that pet has then passed it to another person.”
Can Ferrets Be Tested for the Novel Coronavirus?
In mid-March, the veterinary diagnostic laboratory IDEXX reported that as part of validation for a new PCR test for the novel coronavirus for animals, thousands of cats, dogs, and horses were tested and none were found to be positive. The samples came from the United States and South Korea, and this has been expanded to Canada and Europe.
IDEXX was contacted about whether this PCR test had been validated for ferrets or if there were any inferences that could be made about if the test might work for them as well. At this time, no ferrets have been tested and so no such inferences can be made.
This test is not currently available by the lab, as most evidence currently supports only human to human transmission. However, they state that if findings change, supporting routine testing for pets, they are prepared to make the test immediately available.
So while a select few pets have been tested, like the dogs in Hong Kong, the cat in Belgium, or the tiger at the Bronx Zoo, public health officials are only testing select cases where they feel testing is warranted, and there is no widely available commercial testing for pets.
What Does This Mean for Me and My Ferret?
Recommendations for our pets regarding the novel coronavirus are constantly evolving. But so far, the good news is that you don’t have to treat your ferret any differently than another member of your family.
During the WSAVA webinar, Jim Tedford, President and CEO for the Association for Animal Welfare Advancement, stated that if you get sick, you need to have a plan in place for your pets, but that plan should not include taking them to a shelter or abandoning them. Just like you would have a plan in place for your children, make sure your pets are well-cared for. “A shelter is not the place for pets during this pandemic by any stretch.”
Dr. July Levy, a veterinary professor of shelter medicine at the University of Florida and a member of the WSAVA webinar stated the same. “We are really emphasizing keeping exposed pets with their families.” she said. Regarding a pet if a family member becomes ill with COVID-19, Dr. Levy said, “It’s much better if they can stay in the home or be given to a friend or family member to take them than coming into the shelter.”
So, with the wealth of information we’ve discussed, let’s consider the following summary of points.
- Experimentally infected ferrets can harbor and shed COVID-19 virus. However, they are exposed to much higher levels of virus than a natural infection, and when exposed at lower levels, ferrets don’t shed virus.
- When experimentally-infected ferrets do shed virus, it appears to be only for 4-6 days of infection.
- It’s possible a human could transmit COVID-19 virus to a ferret, but likely only in cases where higher levels of virus are being expelled. This is most likely during significant symptoms of respiratory disease, or shortly before these signs develop. Even then, it’s unlikely that ferret will be able to shed virus in levels high enough to infect another human.
- Experimentally-infected ferrets can transmit virus to one another. It’s unclear if they could still do this in a natural setting, but this also seems unlikely.
- Ferrets generally don’t appear to get significant signs of respiratory disease when infected with even high-levels of COVID-19 virus and no ferrets have developed the severe pneumonia seen in people. No ferrets to date have died from the disease.
Multiple veterinary, animal, and human health authorities, including the World Small Animal Veterinary Association, American Veterinary Medical Association, World Health Organization, and Centers for Disease Control have made reasonable guidelines for pet parents to follow based on current information.
Using the above points and combining them with the generally accepted guidelines for pets during this crisis, we can start to paint a picture of some good recommendations more specifically for ferret parents at home.
Guidelines for Ferrets with COVID-19 and Their Caretakers
- If a ferret gets infected with COVID-19 virus, it is most likely to be from an infected human, and likely only a symptomatic or presymptomatic person shedding high levels of virus. If you aren’t showing signs of COVID-19, there is no reason to separate yourself from your ferret, any more than it would be reasonable to separate yourself from another member of your family at home. It is still essential that you are all practicing social distancing when outside the home.
- Just like social distancing guidelines for people, you should not be taking your ferret outside to interact with other people outside your immediate home, and any play dates with other ferrets outside the home should be avoided.
- There is NO practical reason that you need to give up or abandon your ferret in order to keep you or your human family from getting the virus. If your ferret has been living with you since this crisis started, the only way he or she could be exposed to the COVID-19 virus is if an infected person brought it in.
- If you are exhibiting any signs of COVID-19-like illness, and especially if you have tested positive, it is recommended to separate yourself from your ferret and have another, asymptomatic member of the home care for him or her. Alternatively, if you live alone and are self-isolating, use a mask and gloves around your ferret, as well as appropriate disinfecting products for bowls, cages, bedding, etc. Make sure to use the same precautions for emptying litter pans/boxes and ensure that urine and feces are removed into closed trash bags and disposed of properly. The main reason to still take these precautions is that if you are hospitalized for the virus, you need to make sure that the person taking over care of your ferret while you are absent is protected as much as possible.
- Make sure to have a plan A, plan B, plan C, etc., in place to care for your ferret and any other animal companions you have in your absence, similar to plans you would have for your children or other family members. At this time, because pets don’t develop serious illness from this virus and are considered a very low transmission risk to people, it’s widely recommended that pets should stay in the home, even if a household member becomes symptomatic for COVID-19.
- The COVID-19 virus is primarily transmissible through respiratory secretions (like coughing) and close contact with an infected human. Surfaces like counters, door handles, etc., are less involved with transmission, but this is especially true for porous surfaces. The virus was found to thrive for less than 24 hours on cardboard, which is less porous and dynamic than a pet’s fur coat. The virus is unlikely to survive long on ferret fur. Basic handwashing should be sufficient to inactivate any small amount of virus that could possibly be transmitted from the coat to your hands.
- Bathing pets to prevent human transmission is no longer being widely recommended because the transmission risk from a pet’s fur is considered to be low. However, if you feel the need to still take this precaution, make sure to use only approved shampoos or Dawn dish soap. DO NOT use any disinfectants or chemical cleaners like bleach directly on a pet.
- If you are asked to care for a ferret owned by someone who is being treated for COVID-19, use your best judgement according to your comfort level. These pets still need care and should stay in their home and not be moved to another location if possible. If you have to move a ferret from the home of a COVID-19 patient into your own, make sure to isolate the ferret for 14 days from all other family members and pets as a precaution. In either case, use appropriate measures to care for the ferret, as we’ve already reviewed, using a mask, gloves, limiting direct contact, and disinfecting surfaces. Although the risk for a ferret to transmit the virus to a person is universally thought to be very low, carefully consider volunteering if you or anyone in your home have any underlying health conditions.
Yes, this coronavirus outbreak is scary, and new information comes out on almost a daily basis. But in order to avoid taking rash actions out of panic and fear, we have to take what we know and make the most logical conclusions from that information.
As far as ferrets and coronavirus go, much of what we know comes from a lab setting. Our brave ferret friends are helping to make a big difference understanding this novel virus as well as paving the way for prevention and treatment options.
The research lab, including the amount of virus a ferret is exposed to, is not the same as what is seen in a natural setting, and we have to remember this as more research involving ferrets continues to come out.
Ferrets are affected by other, more common respiratory illnesses, just like we all are. So if your ferret starts to sneeze, don’t assume that he or she has coronavirus. And remember, that if you yourself don’t have symptomatic COVID-19, and your ferret lives with you, your ferret can’t somehow have contracted signs of the disease when no one in your household has.
And even if you were symptomatic, and transferred coronavirus to your ferret through coughing, your ferret would likely no longer be able to shed the virus after a 6-8 day period or be able to give it to another ferret or human.
So, treat your ferret just like any other member of your family. Follow social distancing guidelines, stay at home as much as you can, and both you and your ferret pal will make it through together.
1 Virus definition. Scitable by Nature Education. https://www.nature.com/scitable/definition/virus-308/. Accessed 4/1/2020
2 M Woolhouse et al. Human Viruses: Discovery and Emergence. Philos Trans R Soc Lond B Biol Sci. 2012; 367(1604): 2864–2871.
3 Ng, P., Böhm, R., Hartley-Tassell, L. et al. Ferrets exclusively synthesize Neu5Ac and express naturally humanized influenza A virus receptors. Nat Commun. 2014; 5, 5750. https://doi.org/10.1038/ncomms6750
4 Belser, JA, Barclay, W, and Barr, I et al. Ferrets as Models for Influenza Virus Transmission Studies and Pandemic Risk Assessments. Emerging Infectious Diseases. 2018. Vol. 24, No.6. www.cdc.gov/eid
5 Yushun, W, Shang, J, Graham, R, et al. Receptor Recognition by the Novel Coronavirus from Wuhan: an Analysis Based on Decade-Long Structural Studies of SARS Coronavirus. Journal of Virology. 2020; Volume 94, Issue 7.
6 Vaduganathan, M, Vardeny, O, Michel, T, et al. Renin-Angiotensin-Aldosterone System Inhibitors in Patients with COVID-19. The New England Journal of Medicine. Special Report. 2020. Accessed through NEJM.org. Accessed 4/1/2020.
7 CDC: Severe Acute Respiratory Syndrome. https://www.cdc.gov/sars/about/fs-sars.html. CDC. Accessed 4/1/2020
8 Van Dormalen, N, Miazgowicz, KL, Milne-Price, S, et al. Host Species Restriction of Middle East Respiratory Syndrome Coronavirus Through Its Receptor, Dipeptidyl Peptidase 4. Journal of Virology. Vol 88. Number 16. Pp 9220-9232.
9 World Health Organization. Middle East respiratory syndrome coronavirus. World Health Organization. https://www.who.int/emergencies/mers-cov/en/. Accessed 4/1/2020
10 Griffin, G, and P Locke. Comparison of the Canadian and US Laws, Regulations, Policies, and Systems of Oversight for Animals in Research. Ilar Journal. 2016; Volume 57, Issue 3, pp 271-284.
11 Chen, H. Susceptibility of ferrets, cats, dogs, and different domestic animals to SARS-coronavirus-2. Pre-print. 2020, March 30. Accessed through bioRxiv.
12 O-Neill, N. Second dog in Hong Kong tests positive for coronavirus. NY Post. March 19, 2020. https://nypost.com/2020/03/19/second-dog-in-hong-kong-tests-positive-for-coronavirus/. Accessed 4/1/2020
13 Kim Y, and Kim S, et al. Infection and Rapid Transmission of SARS-CoV-2 in Ferrets. Journal pre-proof. 2020, March 23. Accessed through CellPress.
14 S Mallapaty. Coronavirus can infect cats–dogs, not so much. Nature. April 1, 2020. https://www.nature.com/articles/d41586-020-00984-8. Accessed 4/3/2020.
15 Lappin M, Tedford J, Levy J. Guidance for COVID-19 Community Response for Non-Profit, Government, and In-Practice Veterinary Personnel. World Small Animal Veterinary Association. Webinar. April 3, 2020. https://wsava.org/wp-content/uploads/2020/04/COVID-19-An-Update-for-WSAVA-Members-April-3.pdf
16 IDEXX. COVID-19 customer resources, frequently asked questions. https://www.idexx.com/en/about-idexx/covid-19-resources/. Accessed 4/1/2020.
17 Maniatis, J, IDEXX representative, personal email communication.
18 American Veterinary Medical Association. COVID-19: What Veterinarians Need to Know. https://www.avma.org/resources-tools/animal-health-and-welfare/covid-19. Accessed 4/1/2020
19 Veterinary Information Network. COVID-19 FAQ. Veterinary Information Network. https://www.vin.com/members/cms/project/defaultadv1.aspx?id=9548140&pid=11200&. Accessed 4/1/2020
About the Author
Chris Vanderhoof is a veterinarian practicing in the Washington, D.C. area of the United States. He earned both his veterinary medicine degree and master of public health degree from the Virginia-Maryland College of Veterinary Medicine in 2013. In his free time, when not in the clinic or spending time with his family and 3 cats, Dr. Vanderhoof writes for the animal health and public health fields.
Quick note from the Founder of Ferret-World.com, Stephanie Warzecha:
We always try to deliver you with the highest quality, scientifically-backed information on ferrets as we possibly can. However, please note that there is a lot more to health than what science has funds for. There are many areas in science that have not been studied due to a lack of funds. For example, we don’t have any peer-reviewed veterinary studies that would examine the different types of diets that ferrets are fed and the impact that would have on their ability to fight viruses and disease. We don’t know what foods, genetics, environments, and stressors lab ferrets have, which could impact their immune systems and how that would compare with our pet ferrets.
Similarly, in human studies what bothers me is that there always seem to be funds for pharma backed medicine and vaccines which generate millions of dollars in revenue for those companies, but never any studies on natural remedies or how we can empower ourselves to create the healthiest immune systems to best support ourselves during times of stress and crisis, such as what we are going through now.
In a nutshell, I don’t support or condone big pharma or The World Health Organisation. However, I do like to stay aware of how money and power can corrupt people and organizations.
There is a lot of information that is coming out now that I feel shows that we should all stay aware of how human freedoms are being taken away at this point in history, which I do not support. Some of the organizations mentioned in this article may not be as concerned with human or animal health as first meets the eye.
I don’t want you to think that just because we mention specific organizations in this article, that we support them in any way. I encourage you to do your own independent research on these organizations and make sure that they truly have integrity in helping humans and animals, and that they are not just influenced by money, greed, and power.
However, for the purpose of this article, these were the most credible mainstream sources that we could find for the purpose of this topic.
This is just my personal opinion and not reflective of the writer’s opinion or experience in any shape or form.