April 24, 2020 – COVID-19, a respiratory illness caused by a type of coronavirus, has dominated the national and international news since word first spread of a new, serious respiratory disease in China. Today, communities globally are struggling with this pandemic, hundreds of thousands of people have been infected, thousands have died, and life as we know it has changed dramatically with stay-at-home orders and social distancing as governments seek to stem the rate of infection.
In the midst of this crisis, so many questions are being asked about COVID-19 as researchers strive to find answers. This includes caring pet owners who are concerned about the health and well-being of the animals that share their lives and homes. It’s important for all pet owners to know the facts, so they can filter out the fiction, about coronaviruses.
Viruses are everywhere
Viruses are tiny infectious agents that are just small packages of genetic material with an outer coating. Viruses don’t have the machinery to multiply on their own – they must invade a living cell to make more virus particles. Once inside a cell, the viruses take over the cell’s resources and rewrite the cell’s operating instructions to successfully multiply. In many ways, viruses act like cellular parasites. Once the viruses have multiplied, they burst out of the cell and the newly produced viruses find other cells to infect or leave the body in droplets when a person coughs or sneezes.
There are billions of viruses in the world – by one estimate, there are more than 10 million times more virus particles on Earth than there are stars in the universe. That’s a LOT of viruses.
Viruses come in many shapes and sizes, from tiny parvoviruses to the giant mimivirus. Viruses can be circular, rod-like, or thread-like, and can infect animals, plants and even bacteria! But they’re so tiny, we require a specialized electron microscope to see them.
Viruses have a bad reputation because many important diseases, such as rabies, are caused by viruses. But the truth is that many viruses live in harmony with their hosts – in fact, some viruses might actually help a host by, for example, boosting our immunity to keep disease-causing viruses out! However, the reverse also is true; many serious diseases are caused by viruses. Sorting the good from the bad is a tricky field of research unto itself.
Where do coronaviruses fit in?
Coronaviruses are a family of viruses found around the world, in many diverse animal species and in many different environments. There are lots of different types of coronaviruses, some responsible for known diseases in animals, and others that seem to circulate harmlessly.
We know that the virus responsible for COVID-19, known as SARS-CoV-2, likely originated in bats, maybe through another species. Regardless of the exact chain of events, it’s clear this disease outbreak resulted from something called spillover.
Spillovers and zoonoses – what do they mean?
Spillover is a phenomenon where a virus or other pathogen moves from one animal to another, and it is a growing problem in both people and animals and between livestock and wildlife. Increased contact between species is a result of many compounding factors. These include habitat encroachment, domestic animal grazing in previously wild areas, and markets where multiple domestic and/or wild animal species are mixed (as often seen in novel influenza outbreaks), as well as climate change. All increase the chances that spillover events occur.
A zoonotic disease is defined by the Centers for Disease Control as a disease passed from animals that can make people sick. Common zoonotic diseases include Salmonella infections, ringworm and rabies, just to name a few. But disease transmission is not a one-way street. Reverse zoonosis can occur when humans infect animals. One example of this is the infection of chimpanzees with human respiratory viruses, often with deadly consequences.
The line between a zoonotic disease and a spillover event can be fuzzy. In a paper published before the current COVID-19 outbreak, by Morris Animal Foundation-funded researcher and Wildlife Scientific Advisory Board member Dr. Raina Plowright, the authors discuss in detail how a number of factors need to align for spillover to occur.
Factors include how the pathogen survives, develops and is spread by the animal species source of infection, as well as the route and dose of exposure and the human recipient’s bodily defenses. In all, it must be the perfect storm of events. As our current pandemic proves, this alignment can and does happen, with sometimes dire consequences. The World Health Organization estimates that annually approximately three known spillover events leading to human disease outbreaks occur, though many others likely go undetected because one person may be infected and recover or die without the cause being discovered and/or before the disease can be transmitted to others.
What about coronaviruses in pets?
As mentioned earlier, coronaviruses are common. Veterinary scientists have long recognized these types of viruses in many domestic animals, including dogs and cats. Most coronaviruses in animals are found in the gut, where the severity of disease can vary significantly. In addition, around the time of the first SARS outbreak, a respiratory coronavirus was found in the United Kingdom (at the Royal Veterinary College) to be a component of kennel cough infections in some dogs.
Feline infectious peritonitis (FIP) virus is one type of fatal coronavirus that only affects cats. The virus is a mutant form of the more benign feline coronavirus that almost all cats are exposed to sometime in their lives. In a small percentage of cats, the benign virus mutates for reasons that aren’t completely understood into the deadly FIP virus resulting in severe and fatal disease.
The good news is no evidence exists that any coronaviruses found in cats or dogs can be transmitted to people. Even better news is that the decades of research done on feline infectious peritonitis virus now is helping human researchers tackle the problem of vaccine development in the current COVID-19 pandemic.
What has Morris Animal Foundation done to help?
The Foundation is a leader in feline coronavirus research. In the last 15 years, more than $2 million has been invested in innovative studies focused on projects ranging from basic bench research to improvements in diagnostic testing to vaccine development.
We are proud of our funded researchers, especially now as we see many of these same researchers recognized for their outstanding work on coronaviruses during this pandemic.
A notable example is Dr. Gregg Dean, Professor and head of Colorado State University’s Department of Microbiology, Immunology and Pathology. Dr. Dean has been working on a Foundation-funded grant to develop a vaccine against feline coronavirus, but recently expanded his research program to include work on developing a vaccine against SARS-CoV-2.
“Our work on a feline coronavirus vaccine has allowed us to quickly engage in work to assess the same approach against SARS-CoV-2/COVID-19,” said Dr. Dean. “I strongly believe the lessons learned over years of work by many investigators to develop a vaccine for cats can be directly applied to the current pandemic.”
Dr. Gary Whittaker is another Foundation-funded researcher in the news. Dr. Whittaker is Professor of Virology in the Department of Microbiology and Immunology at Cornell University. His work on the basic biology of feline coronavirus, including how it infects cells, has caught the attention of researchers around the world working on solutions for the current pandemic.
In other work, a breakthrough antiviral treatment for cats with FIP was developed by a Dr. Yunjeong Kim, Associate Professor in the Department of Medicine and Pathobiology at Kansas State University. The drug is still in the development stage and not yet available to clinicians, but could join the list of drugs used to fight other coronaviruses. This research also was funded in part by Morris Animal Foundation.
“We found that most of cats, except for those with neurological disease, can be put into clinical remission quickly with antiviral treatment, but achieving long-term remission is challenging with chronic cases. These findings give us more insight into FIP pathogenesis and also underlies the importance of early diagnosis and early treatment” said Dr. Kim.
Morris Animal Foundation has always been on the leading edge of science to advance animal health. To learn more, check out our COVID-19 information page, our investments in feline infectious peritonitis and all the Foundation’s work on infectious diseases. What we learn about animal diseases can have major implications for the health of all species, including humans