1 May 2020
The COVID-19 pandemic has affected all walks of life – including the veterinary profession – in an unprecedented way. Here, with Alan Radford, RCVS Knowledge takes a look at the science of the virus, and how this informs approaches we should take to help slow its spread.
To start at the beginning, the SARS-CoV-2 virus causing such devastation around the world is a member of the family of coronaviruses.
A large number of coronaviruses exist that are responsible for a range of diseases in a number of species. These include:
While SARS-CoV-2 – the cause of COVID-19 – is proving extremely virulent to some people, the danger posed by the other coronaviruses varies considerably. It’s worth remembering some of the viruses that cause the common human cold also fall into this family.
As vets and veterinary nurses, we’re already familiar with coronaviruses and they’re a common part of veterinary practice. These veterinary viruses (excluding the bat viruses) are very distinct from the human coronaviruses, so while a pet or animal may have a coronavirus, this is in no way related to the coronavirus causing such concern at the moment.
It is, therefore, advisable to use the medical names of these animal viruses when referring to them with clients – for example, FIP virus rather than “coronavirus in cats” – to avoid causing unintentional and misplaced alarm.
Like all viruses, coronavirus is an obligate intracellular parasite, which means, unlike most bacteria and fungi, it needs a host cell to divide and replicate. All coronaviruses have an RNA genome, which means they can mutate and evolve quickly – in part, explaining their all-too-frequent emergence into the human population.
However, on the positive side, the virus is encased within a lipid envelope, which means the virus thankfully has an Achilles heel. The envelope is derived from the cell membranes of the host cell the virus replicates in, and is essential for its infectivity.
Just like these cell membranes, the viral envelope is lipid – an oily or waxy type of organic molecule – which makes it quite fragile. This means coronaviruses are generally quite short-lived in the environment, and relatively susceptible to soap and alcohol-based disinfectants. This is why thorough and regular hand-washing is so important for the control of transmission between humans, and is one of the major tenets of the Government’s control strategy.
The lipid nature of the envelope means you don’t have to use a specially formulated product for veterinary practice to disinfect for coronavirus effectively – many household bleaches will work perfectly well.
Government advice for cleaning around COVID-19 patients in non-health care settings recommends either a combined detergent disinfectant solution at a dilution of 1,000 parts per million available chlorine (ppm av cl), or a household detergent followed by disinfection (1,000ppm av cl).
Equally, you can continue to use your standard detergent for washing your clothes and uniform. Simply make sure you wash at the highest temperature the fabric can tolerate, and dry items completely.
So, can animals get ill? While more evidence is needed, our present belief is, while some species may rarely get infected, like humans, they seem clinically well or only have mild signs.
Obviously, those animals that live with COVID-infected people may also get the virus on their coat, but such animals will not be unwell. On this basis, you can feel relatively confident reassuring clients that the risk of their pets or animals falling ill with the virus is low. However, it would be sensible not to rule it out, and practitioners should be mindful of the risk when treating sick animals that have been in contact with COVID patients.
Both the Small Animal Veterinary Surveillance Network and VetCompass are also looking for any evidence that patterns of disease are changing.
The second question is: can pets transmit the virus? Both as fomites and when infected, this seems possible. However, we must keep this risk in context. Based on current evidence, the vast majority of people who unfortunately get SARS-CoV-2 will get it from other humans and not animals.
That said, we can take sensible precautions to minimise this risk. We should reduce our handling of all fomites, and this sensibly includes animals. So one simple thing to consider in practice is what cases you can postpone – do check the latest guidance from the RCVS.
When we do handle animals in practice that may be infected or fomites, a range of precautions can be taken, depending on the level of risk inherent in each case. As a baseline, we should preferably wear gloves when handling animals, or carefully wash hands according to Government protocols before and after examining the animal. It’s not currently recommended to wear face masks as a routine – it’s more important to avoid touching your face.
However, we must also be asking owners of animals whether the household unit has suspected or confirmed COVID-19 disease.
If you deem it absolutely necessary to see such an animal from these households (especially cats and ferrets), it’s recommended – at the time of writing – you wear gloves, a disposable apron/suit and face mask. You should escalate to eye protection – such as goggles – if a splash or aerosol risk exists, such as where the pet is coughing or sneezing, or you feel it is necessary to carry out dental work or intubate.
RCVS Knowledge has produced specific personal protective equipment guidance in partnership with industry practices, which is updated regularly, so do check this, given the potential for this to change over time.
In summary, the structure of coronavirus means if we make consistent, concerted efforts to observe the aforementioned washing, cleaning and protective measures, we can play our part in stemming the spread of the virus, while continuing to deliver on our commitment to relieve animal suffering.
Stay up to date with COVID-19 guidance – including the latest evidence and webinars – at rcvsknowledge.org/covid-19
