Recently, a dog in Hong Kong tested positive for COVID-19 raising concerns that we can pass the virus to our pets and our pets can pass it to us. The dog was placed in quarantine and retested over several days. After the dog continued to test weak positive, it was determined that the dog did have COVID-19 but that it is not causing any clinical signs. The Chief Veterinary Officer at the American Veterinary Medical Association commented on the case, stating that the dog’s apparent health in the wake of infection indicates that the virus isn’t replicating well enough to make the dog ill (more on viral replication below in the “Transmission” section). At first, authorities were considering the possibility that the dog was just contaminated with the virus but the repeated positive test results confirm infection. Now, it appears that the dog is a “dead-end host.” This means that the disease can be transferred to the animal but cannot be transferred beyond that to other species or the same species. So it cannot be passed to humans or other dogs.
COVID-19 is the coronavirus strain that is infecting people worldwide, causing a respiratory disease. In people, symptoms include coughing, sneezing, difficulty breathing, fever and tiredness. The disease is life threatening in a portion of the population, specifically those who are elderly or immunocompromised. In others, the disease has mild or no symptoms.
Every day, we are learning more about COVID-19 and the doctors at Vet’s Here are remaining up-to-date and want to keep you in the know. I’ve put together some background information to follow up with the latest update.
Transmission: How do COVID-19 (and other viruses) infect multiple species?
There are several viral adaptations that have allowed certain strains of coronavirus to be transmitted from animals to people. Viruses infect the body by using proteins to bind to specific receptors on cells. In the case of COVID-19, the virus uses a protein that can bind in lots of different ways allowing it to bind to a variety of mammalian cells. Usually, species-specific strains in animals don’t spread to humans for several reasons including; 1) they don’t have the right protein to bind to human cell receptors or 2) they are so foriegn that our body catches and eliminates them before we become sick.
Sometimes viruses get around those obstacles through mutation. Coronavirus is an RNA virus. This means that it uses RNA as its genetic material instead of DNA. RNA viruses are prone to mutation because the proteins that read and replicate RNA aren’t as good at proofreading their work as the proteins that read and replicate DNA. Essentially, the proteins that are in charge of making more viral particles are making mistakes and creating new variations of the virus, or mutating virus, all the time. Often, the mutation makes it impossible for the viral particle to survive or be infective. Rarely, a virus will mutate in a way that helps it bind to different cells. That’s one reason a virus that naturally infects bat cells (like COVID-19) can change or mutate and infect human cells. History shows us that, while this is possible, it is relatively uncommon for these species jumps to occur. Often, even when they occur, the virus is so mutated, it is unable to spread in the new species. Remember, there are lots of viruses in the world that have stayed within their own species including coronaviruses in cat’s and dogs!
History: Coronavirus in different species.
Some media sources have been referring to coronavirus and COVID-19 interchangeably so it is important to note that COVID-19 is a type of coronavirus. There are many types of coronaviruses that affect different species and cause different types of illness.
Dogs: (CRCoV – group 1) Coronavirus in dogs can cause enteritis in puppies. It can affect adult dogs but usually does not cause signs. The disease is uncomfortable but short lived. Dogs present with yellow to orange diarrhea, lethargy, decreased appetite. Dogs become infected when they interact with an infected dog’s poop. There is a vaccine available for this canine coronavirus. Dogs don’t pass this type of coronavirus transmitted to other species.
There is also a canine respiratory coronavirus that is related to a bovine form (CRCoV – group 2). The canine respiratory coronavirus is uncommon in the US (primarily seen in the UK, Ireland, Greece, Italy, Japan). Dogs present coughing, sneezing and with nasal discharge (upper respiratory signs). Respiratory coronavirus in dogs spreads by contact, respiratory secretions and environment similarly to how COVID-19 spreads between humans but the dog form is NOT passed to humans. There is no vaccine for the respiratory coronavirus but you can vaccinate for co-infectious diseases including bordetella, parainfluenza, adenovirus, distemper. This reduces your dogs risk of feeling sick because healthy dogs can usually fight off one illness but if they get multiple illnesses, it can be hard on their immune system. Being very sick also lowers your immune system, making you more susceptible to other illnesses. That’s why getting the flu vaccination is so highly recommended in humans right now.
Cats: (FCov) Coronavirus in cats is so contagious that most cats have been exposed to it and will be positive if tested. Most cats also don’t get sick from this virus but it may cause mild diarrhea in kittens. It is transmitted in the same way as canine coronavirus from cat to cat through their poop. There is a mutation in feline coronavirus that can cause a severe illness called Feline Infectious Peritonitis. Clinical signs include distended abdomen, multi-compartment effusion, lethargy etc. This disease most commonly affects young or geriatric cats. In 2003, there were concerns that the SARS-CoV coronavirus spread from cats to people. Those concerns were unfounded and many pets suffered and lost their families unnecessarily because of it. Cats do not pass their form of coronavirus to people.
Humans: Aside from COVID-19, there are other human forms of respiratory coronavirus. In fact, the common cold is caused by several coronaviruses including HCOV-229E, HCOV-NL64, HCOV-OC43 and HCOV-HKU1. Coronavirus in humans is spread primarily through person-person contact and through respiratory droplets spread by coughing and sneezing. Interestingly, dogs and humans can spread respiratory droplets at similar distances, some estimate the distance at greater than 25 feet. Dogs are just as likely to give us the common cold as they are to give us COVID-19 (not very likely).
There have been other coronaviruses in humans that sparked public concern including SARS (Severe Acute Respiratory Syndrome) and MERS-CoV (Middle East Respiratory Syndrome). COVID-19, MERS, and SARS originated in bats and used other animals as their intermediate hosts. SARS went from bats to civets to humans with a mortality rate of 10% and over 8000 people infected. MERS went from bats to camels to humans with a mortality rate of 35% and over 2,500 people infected. COVID-19 went from bats to pangolins to humans with a mortality rate of 2% with over 140,000 infected, over 5,000 deaths and over 50,000 recovered by present stats.
Remember, there are many different types of coronavirus and other viruses that have existed in our pets across the world and throughout our history that have NOT infected people.
Take Home: What should I do for my pet?
At Vet’s Here, we consider every aspect of your pets life, health and happiness. So of course we care for you, the pet owner! It is so important for you to stay healthy so you can care for your pet! So please keep your hands clean and follow your local and federal guidelines on how to remain healthy and safe. Please also try to keep up with CDC updates for best practices.
The American Veterinary Medical Association recommends that you wash your hands with soap and water for at least 20 seconds, especially after using the restroom, before eating, after blowing your nose, coughing or sneezing; and before and after caring for your animals. Other recommendations include avoiding touching your eyes, nose and mouth with unwashed hands, staying home if you aren’t feeling well and if you’re ill, restrict contact with people and animals alike.
As for your pets, right now there is no proof that COVID-19 can make your pet feel ill. Remember, there have been zero reports of cats or dogs developing any clinical signs after being infected with COVID-19.
If your pet is exhibiting signs of an upper respiratory infection, such as coughing, sneezing, runny nose, or lethargy. Call your vet to make an appointment for an examination. At Vet’s Here, we are constantly updating our protocols to make it safer to get the care you need for your pet without putting your or your family’s health at risk. This includes safe distance pet transfers where we take your pet to our fully equipped mobile veterinary unit to do a complete physical exam.. We are staying up to date on best practices to make the appointment safest for you, your pet and our doctors.