Not all viruses are the same.
Some are relatively easy to destroy with the right disinfectant, while others can survive for much longer in the environment and are considerably harder to kill.
Understanding the difference can help when choosing a disinfectant and putting together an effective cleaning and biosecurity routine.
Enveloped and non-enveloped viruses
One of the biggest differences between viruses is their structure.
Enveloped viruses have an outer fatty layer, known as an envelope. This layer is relatively vulnerable to disinfectants. If the envelope is damaged, the virus can no longer effectively infect cells.
Examples include:
- Influenza viruses
- Canine distemper virus
- Feline herpesvirus
- Coronaviruses
In general, enveloped viruses are easier to inactivate with disinfectants.
Non-enveloped viruses don't have this vulnerable outer layer. Instead, they have a tougher protein shell protecting their genetic material.
This can make them more resistant to disinfectants and better able to survive in the environment.
Two important examples in animal health are canine parvovirus and feline calicivirus.
Why does this matter when choosing a disinfectant?
It means that saying a disinfectant "kills viruses" doesn't necessarily tell you enough.
A product may be effective against some viruses but not others.
When looking at the evidence behind a disinfectant, it's worth asking:
- Which viruses has it been tested against?
- At what dilution?
- How long does it need to be left in contact with the surface?
- What testing has been carried out?
This is particularly important when dealing with tougher non-enveloped viruses.
Using the right disinfectant is only part of the answer
Even a disinfectant with good evidence behind it needs to be used correctly.
Cleaning comes first.
Dirt, faeces, bedding, hair and other organic material can get in the way of effective disinfection. Where necessary, this should be removed before applying disinfectant.
Dilution matters.
If a disinfectant has been proven effective at a particular concentration, it needs to be diluted according to the manufacturer's instructions.
Contact time matters.
Disinfectants need time to work. If a product is wiped away too quickly, you may not achieve the level of efficacy demonstrated during testing.
These are simple things, but they can make a big difference.
Look beyond the headline. Words such as "antiviral" or "virucidal" can sound reassuring, but it's worth looking a little deeper.
The important question isn't simply: "Does this disinfectant kill viruses?"
It's: "Does it have evidence against the viruses that matter in my environment?"
Whether you're responsible for a veterinary practice, kennel, cattery, rescue centre, equine yard or another animal environment, understanding the risks you're dealing with is an important part of choosing the right biosecurity approach.
Because when it comes to viruses, some really are tougher than others.