UK Bird Flu Outbreak: Protecting your Chickens

With the recent outbreaks of avian influenza around the United Kingdom, keepers of all types of poultry have become acutely aware of the risk to their own flocks. As of 6 November 2020, the Animal and Plant Health Agency (APHA) has raised the risk level from ‘low’ to ‘medium’ for avian influenza being introduced onto British poultry premises. This is following a string of confirmed cases in England and in mainland Europe. Both commercial flocks and backyard flocks are at risk, particularly with the movement of migratory birds during the autumn season. Even if you have a few chickens as pets, you should make sure you understand the risks and what to do if you spot the symptoms of bird flu.

What is Avian Influenza/Bird Flu?

Avian influenza is a virus which is carried by wild birds. Each strain is characterized by their “H” and “N” surface proteins. There are 16 types of H proteins and 9 types of N proteins. Viral strains also differ in their ability to cause disease symptoms and are labelled as either high or low pathogenicity. Some strains have been able to modify their virulence to be able to cause disease in humans- you may be familiar with the highly pathogenic H5N1 strain of avian influenza which emerged in 1997 and caused high rates of mortality in people as well as birds.

What are the symptoms of bird flu in chickens?

The symptoms of avian influenza in a flock of birds are variable but often include respiratory symptoms and death. If you notice that your chickens are sneezing excessively, are having difficulties breathing, or are dying suddenly, give your veterinarian a call. They will be able to assess the situation in light of the local avian influenza risk. They may want to investigate further or report the case directly to public health authorities. Avian Influenza is a notifiable animal disease in the United Kingdom and all suspect cases must be reported.

How does bird flu spread?

Bird flu spreads in poultry via bird-to-bird contact or by contact with surfaces contaminated with infected saliva, mucous, or droppings. Wild water birds, such as ducks or geese, can carry avian influenza without showing any symptoms. This means that they can travel long distances without being hindered by illness, and their migration season poses a high risk for wide-range transmission. People can contract human-adapted strains of bird flu from direct contact with an infected bird or from contaminated surfaces. The virus is able to become aerosolized as well, and can cause infection after contact with the mucus membranes of the eyes, nose, or mouth. Avian influenza can also be transmitted to people via the consumption of undercooked eggs. Therefore, it is recommended to dispose of eggs from suspect flocks.

What happens if a vet thinks my flock has bird flu?

If bird flu is diagnosed in a backyard, the situation will be assessed by public health authorities and veterinarians. Recommendations for the infected flock are made on a case-by-case basis, taking into account the risk to public health and poultry flocks in the area. Unfortunately, this viral infection cannot be cured and control of spread is by euthanasia of sick birds. Depending on the strain of bird flu found, you may be required to cull some or all of the birds on your site!

How can I reduce the risk of bird flu in my chickens?
Thankfully, there are measures that any backyard flock owner can take to reduce the likelihood of infection.

Physical Barriers

A physical barrier is the first line of defence against potential disease-spreaders. Keep backyard flocks isolated from waterfowl and wild birds as much as possible by fencing off their range and restricting access to any bodies of water. Limit the number of visitors to your flock as much as you can. Any person who has visited a poultry flock has the potential to carry not just avian influenza but a host of diseases on their clothing which can cause illness and increase susceptibility to infection.

Biosecurity

When you visit your own chickens or poultry areas, use boot dips with a strong disinfectant that is replaced on a regular basis. Use a separate set of clothing that you use only on your site and ensure that they are changed frequently.

You should also keep a closed flock- this means that no birds are introduced into established flocks on the site. Instead, use an “all-in-all-out” system where flocks are always moved in their entirety onto and off of a site. Chicken sheds are then able to be completely cleaned out in-between flocks and there is no mixing of birds from different sources. If this is not possible, quarantine newly-introduced birds for a minimum of 30 days before introducing them to the flock.

Cleaning and Disinfection

All chicken areas should be kept tidy. Your cleaning protocol should include both a cleaning step to remove physical contaminants (dirt, dust, and droppings, for example) and a disinfection step. By law, disinfection should be with DEFRA-approved disinfectant. Remember to include all surfaces in the coop, drinkers, feeders, and any other equipment you use for your backyard flock.

Disease Monitoring

Monitor your chickens closely for symptoms of avian influenza. These include sudden decreases in egg production, respiratory signs, and any unexpected mortality. Remember that the symptoms of bird flu are variable and can be present even in the absence of the abovementioned symptoms. Report health issues promptly to a veterinarian.

Can I vaccinate my birds against avian flu?

People often ask about the use of vaccines against avian influenza for their backyard flocks. In the United Kingdom, vaccines that are used to protect against bird flu are not allowed to be used. Part of the reason for this is because it is challenging to differentiate infected birds from vaccinated birds in the case of an outbreak. Also, even though the vaccine would reduce mortality in the face of an outbreak, vaccinated birds would still be able to contract and transmit the disease. Additionally, there are many strains of avian influenza which have the capacity to mutate rapidly. This makes it difficult to choose which strains to include in the vaccine in the first place, making vaccines against bird flu not very effective.

Where can I get more information?

You can continue to stay up-to-date on the current avian influenza situation in the UK using the information website page released by the Department for Environment, Food & Rural Affairs and the Animal and Plant Health Agency: https://www.gov.uk/guidance/avian-influenza-bird-flu