Evidence of exposure to SARS-CoV-2 in cats and dogs from households in Italy
A recent study involving researchers from SAVSNET sheds more light on the effect of COVID-19 on pets. The paper, published online in the preprint journal BioRxiv shows that a small percentage of dogs and cats living in areas of Italy where COVID-19 is actively circulating in humans develop antibodies to the virus suggesting they are infected. The study involving over 1000 pet animals from Italy confirms earlier smaller studies in cats from China and extends the findings to dogs. It is important to note that none of the tested animals were shedding virus, and as such were unlikely to be infectious.
These results whilst important to understanding the biology of COVID-19, have no impact on already existing advice to pet owners.
Access the paper here
Read our infographic summarising this work here
A note from Dr Shirley Bonner from SAVSNET-Agile on the concerns and joys of a return to the lab.
I am a research scientist. I work in a lab doing experiments on the pathogens that cause respiratory and gastro-enteric diseases in cats and dogs. As for many people, everything changed with lockdown. I had to literally put down my pipettes and walk out of the lab. There was plenty of work to be done at home – writing up work on an outbreak of vomiting in dogs and analysing data that had been waiting for the ‘right moment’. But I found this really hard – my home is at the laboratory “bench”. So I was really pleased when a few weeks into lockdown we were contacted by Dr Ian Patterson at the Liverpool School of Tropical Medicine (LSTM). Ian had a test working in his lab (called a PRNT) to look for neutralising antibodies to SARS-Cov-2 in serum (blood samples). If SARS-Cov-2 neutralising antibodies are present in a patient’s blood it means that they have previously been infected with the virus. He asked whether we had serum samples from animals that we might want to test. At that point in time we were also in touch with Professor Nicola Decaro, a Professor of Infectious Diseases in Animals at the University of Bari in Italy to ask his advice on a separate outbreak of vomiting in dogs we were working on. He happened to say that his lab had collected serum samples from cats and dogs in areas of Italy that had high levels of SARS-CoV-2 in humans and did we know anyone who could test for neutralising antibodies in these samples? A collaboration between SAVSNET-AGILE, the LSTM and the University of Bari was born.
Since I have worked on a similar assay to the PRNT I volunteered to help Dr Patterson and his team to test for neutralising antibodies in the animal sera. SARS coronavirus research was considered as essential work and therefore I would be allowed ‘out’ to do this during lockdown. I was nervous at first about going out in to a world under lockdown. On the way in to LSTM there was very little traffic, the pavements were empty of people and the University campus was deserted. I even had absolutely no trouble parking!! I was a little bit scared of going into what was essentially a new job with people I didn’t know. I quickly got over this when I met the team at LSTM. They were so nice and really pleased I could help them out. Samples started to arrive from Italy. We already knew that the animals they came from had all tested negative for SARS-CoV-2 using a diagnostic test to look for infection (PCR) so we weren’t really expecting to find any neutralising antibodies. We really thought that all the results were going to be negative, so when a few animals tested positive we started to get quite excited about the results and perhaps a bit concerned about what they might mean. In the end we tested 540 sera from 152 cats and 388 dogs and 3.9% cats and 3.4 % dogs had neutralising antibodies. This shows that cats and dogs can be infected with SARS-CoV-2. We also found that dogs were more likely to be positive if a human in their household had tested positive for the virus, suggesting that they are perhaps more likely to catch the virus from their owners. Our results suggest that cats and dogs can get SARS-CoV-2. There is no evidence as yet that pet animals can give the virus to their owners. However, it would be sensible to get someone else to look after our pets if we ourselves have signs of the disease.
It was amazing to work on this project. There have been lots of small bits of research suggesting that the occasional cat and dog have been COVID-19 positive; but this is the largest study of whether pets can get SARS-CoV-2. I’m really proud to have been able to use my skills for something really worthwhile and working with my colleagues at SAVSNET-AGILE and at the LSTM has been a special time in my career…. with a new friend in Italy to boot! It is so exciting to have contributed to research on COVID-19. And I think my cat has been looking at me with a little more respect….