Updated 31-10-2022: As there have been another eight cases in England and one in Scotland between 27 and 31 October, APHA has decided that as from one minute past midnight on 7 November 2022, all poultry and captive birds in England will be subject to a housing order. This means they have to be kept indoors regardless of the type of bird or the size of the flock, in order to slow the spread of avian influenza (bird flu), and bird keepers have to follow strict biosecurity measures.
The UK is in partial lockdown again. No, not a Covid lockdown for the humans, a partial lockdown for birds, to try to slow the spread of Avian Influenza H5N1.
H5N1 has been spreading worldwide for the last 15 years. It is very contagious to many species of birds, and wild birds are affected as well as poultry, so the chances of eradicating it are slim. It causes illness and mortality among birds, and the production of eggs is affected while the flock is suffering with the virus. For this reason, it is a problem, both from an animal welfare point of view, as well as an economic point of view.
H5N1 has been around for a while, and like all self-respecting viruses mutates regularly to keep evading the target animal’s immune systems. This version seems to have evolved in 2021. It affects more bird species than the previous mutations and is showing no sign of ‘fizzling out’.
It can affect humans, but those cases are rare (and are mostly people who work very closely with infected birds) and mild. For birds however the infection is not mild, and mortality rates of up to 60% in domestic poultry have been reported. But some wild bird species can be infected without showing signs of illness, while other wild species have a mortality rate of 10% or more.
Avian influenza is notifiable
H5N1 is notifiable in the UK, which means that if you see an animal that you suspect has the infection, you have a duty to inform the government, in this case the APHA (Animal Plant and Health Agency). This also goes for finding dead wild birds, if you find:
- One or more dead bird of prey or owl
- Three or more dead gulls or wild waterfowl
- Five or more dead birds of any species.
They will then decide on the next steps of action, which in case of a poultry farm is likely to be closing the farm (so no infectious materials or birds can leave the premises) and a visit of an official to the farm to assess the situation and take samples for testing.
If the tests are positive, all the animals on the farm will be culled (euthanised). APHA will then send an email around to all vets in the UK to inform them of a diagnosis of a notifiable disease. A three kilometre protection zone and a 10km surveillance zone will be placed around the premises.
Since 1 October, there have been 73 cases of confirmed highly pathogenic H5N1 avian influenza in England (Scotland and Wales suffer similarly), with wild birds dying as well. For this reason, the government has decided on protective measures.
The recent prevention zone
From 12pm on 17 October, an ‘Avian influenza prevention zone’ was declared across the whole of the UK. The hope is that it will slow the spread of the virus and at least protect domestic birds from contracting it. The virus is not airborne but spreads through contact with infected particles, so locking down the birds restricts the chances of farm birds getting the virus. Unfortunately, because the virus also affects wild birds, we cannot eradicate it from the country.
In most areas, birds do not have to be kept completely indoors, but they can’t have access to ponds or waterways. In addition, the amount of people visiting a farm or premises has to be limited, and disinfection of clothes, shoes and materials used has to be undertaken.
If these arrangements are not effective enough in halting the spread, the next step would be a complete lockdown where birds are not allowed any access to the outside world. This would have serious effects on bird welfare (and would mean no more free-range birds).
A housing measure in a small area
In Norfolk, Suffolk and parts of Essex however, the situation was worse than in the rest of the country. Those areas are subject to a ‘housing measure’, which means all birds have to be kept indoors. This is a difficult situation. It means some animals will be locked in their coop (their night housing).

But this housing is not designed for allowing exercise, so these birds can suddenly be cramped, which can cause pecking and fights between them. The keeper of the birds will have to work a lot harder as well as cleaning the coop. In addition, more electricity is needed to provide daylight so the animals don’t lose their circadian rhythm and will keep on laying eggs.
More eggs will be damaged by the birds. And if the animals still have to be cooped up after the ‘grace period’ of 16 weeks, the eggs can no longer be sold as ‘free range’ and are suddenly worth less money. So more labour, more costs and less income.
In the areas where a housing measure is in place, everyone has to keep their birds inside. Even people with only a few backyard chickens, who maybe rescued them via Chicken Rescue UK or the British Hen Welfare Trust, have to keep them indoors. But they may not be registered with APHA, and therefore not get email notifications about this from APHA. (Registration with AHPA is a legal requirement only if you have over 50 birds of the same species or more than one species).
So how do these bird keepers even know? Local papers and radio will report it, and AHPA emails all veterinary surgeons and asks them to inform any of their registered clients who have poultry. But not many people who have a few hens will have them registered with a vet, and many of these animals will not be housed indoors simply because the owners don’t realise it is law, or maybe because they don’t have a suitable coop for them. A run is not ‘indoors’, and that is what most backyard coops have.
Whether or not this will make a difference about the virus spreading is a question we cannot answer. Wild birds will fly around and infect the waterways, so what will locking up a few backyard birds here or there achieve? Still, it’s the law, and this law is in place for a reason. It might help.
Is vaccination not possible?
We do not vaccinate against H5N1. There is no vaccine, and scientists do not think any vaccine that might be developed would prevent infection or spread, just prevent serious disease in most vaccinated animals.
Vaccination is not practical if you have a few thousand chickens and the vaccine has to be administered to each animal individually, like a flu vaccine would (for some other chicken diseases a vaccine can be administered as an aerosol into the stable). Furthermore an influenza virus can mutate rapidly, rendering any vaccine useless, and wild birds can’t be vaccinated. These are all reasons why so far vaccination is not expected, practical or effective in controlling H5N1.
Attempting to vaccinate would cause stress to the birds, be an added financial burden to the farmers, and necessitate more handling of the animals and possibly infections in humans.
All this means at the moment is that vaccination is not an option.