During the Ebola epidemic in 2014, Excalibur, a companion dog living in Madrid, Spain was euthanized due to possible exposure to the virus from his caregiver. This sparked a huge outcry from veterinarians and animal lovers around the world because he was not tested for the virus; there was limited evidence that companion pets could be infected with Ebola virus; and, more importantly to public health officials, there was no evidence that companion pets could transmit the virus to humans or other animals.
The euthanasia of Excalibur was not the first time that fear and panic during viral outbreaks led to ending the lives of companion cats and dogs. Sadly, however, he serves as an angel sentinel being the example everyone points to when we think of companion animal euthanasia during epidemics or pandemics.
When we reflect on the COVID-19 pandemic and the response by public health officials regarding companion pets, we finally are seeing the recognition that these companions play an important positive role in maintaining our mental and behavioral health. The evidence showed only a very, very low potential risk of COVID-19 transmission to humans from pets.
What about the risk to companion pets from these two and other reemerging human viruses that we continue to hear about? The short answer is the risk of transmission of avian bird flu, Ebola, COVID-19, polio (poliomyelitis), respiratory syncytial virus (RSV), and human influenza from companion pets is very, very low. With certain viruses, companion pets may become infected, develop mild symptoms, mount an antibody response, and recover, but will not pass them on to humans. BUT, Monkeypox is another matter.
Bear in mind, we should never say “never” regarding zoonotic spread of viruses, fungi, bacteria or parasites. Microbes need to mutate to survive, and one way to survive is to find a new host. Think about it this way, your heater is on the fritz and the temperature outside is below zero. So, you may stay with a friend for a few days to live. Anyway, the potential – while very unlikely – is always minimally possible with avian bird flu, polio, Ebola, COVID-19, RSV and human influenza.
Why do we continue to refer to the risk of disease to humans instead of companion pets? While public health officials have evolved their thinking regarding companion pets, their concern is the risk to human health – not pet health. In many places to this day, dog bite laws such as this still exist: “It shall be lawful for any person to kill a dog, wearing a collar with a rabies vaccination tag attached, when the dog is caught in the act of chasing, maiming, or killing any domestic animal or fowl, or when such dog is attacking or attempting to bite a person.” One reason is rabies is transmissible to humans from companion pets.
Instead of quoting health websites regarding these viruses and companion pets, we compile the links so you don’t have to search each one individually.
Avian Bird Flu
Centers for Disease Control and Prevention (CDC), Bird Flu in Pets and Other Animals
Hemopet, What We’re Watching: Highly Pathogenic Avian Influenza Virus H5N1
COVID-19
CDC, Animals and COVID-19
CDC, Information about COVID-19, Pets, and Other Animals
CDC, What You Should Know about COVID-19 and Pets
Ebola
To be clear, the federal Centers for Disease Control (CDC) and the American Veterinary Medical Association (AVMA) both affirm that while there is some limited evidence that dogs can become infected with Ebola virus, there is no evidence that they can develop the disease or transmit it to other animals or humans.
In Madrid, Spain, Excalibur, the 12-year-old dog of Spanish nursing assistant, Teresa Romero, who was infected with the Ebola virus, was required to be euthanized by the Direccion General de Ordenacion e Inspeccion Consejeria de Sanidad. The decision was based upon two differences between the circumstances surrounding Excalibur and that of Bentley, the Cavalier King Charles Spaniel of Ebola-infected Dallas nurse, Nina Pham, who was recently reunited with her dog.
Excalibur was in close contact with Romero for five days before the infection was confirmed versus Bentley who was exposed for only the first two days of clinical infection when viral loads are lower and less likely to spread. The Director also pointed out that Spain lacks the pet care infrastructure needed to handle such cases. Additionally, the office cited the 2001-2002 National Institutes of Health study in Gabon stating that several unknown variables exist surrounding the transmission of Ebola. While I understand the reasoning here, I disagree with the decision to euthanize Excalibur, when quarantine and further diagnostic testing for the presence of Ebola virus or antibody could have been offered as a safe and humane alternative.
The same study is also cited by the AVMA, which adroitly points out that while antibodies against the virus were found in 25% of dogs in the area, no virus was found in the dogs. This means that there was evidence of prior exposure to the Ebola virus but no evidence of current infection. Further, none of the animals showed relevant clinical signs or died of the disease during the study period. The CDC concurs with the AVMA position statement here.
Influenza
The CDC has canine influenza listed as transmissible to humans. This is not true. Please refer to the AVMA on this subject, Canine Influenza FAQ. You can also read Hemopet’s blog post, A Survey of Canine Immunity to, and Vaccines for, Newer Flu Viruses.
Avian Bird Flu is influenza that mainly affects birds. We wanted to distinguish it from human and canine influenza. Please refer to the links above for information on that.
Human influenza does not affect companion dogs or cats at this time.
Monkeypox
CDC, Monkeypox – Pets in the Home
Polio (poliomyelitis)
The CDC makes no mention of polio and companion pets. The detection of polio in New York’s wastewater earlier this year is a good reminder why we need to maintain proper handwashing because it is primarily spread through contact with human feces – even minute pieces!
RSV
There is no mention of companion pets contracting or transmitting RSV to humans.