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Avian Influenza

Animal Health investigates all incidents of suspected notifiable disease. If you suspect signs of a notifiable disease, you must immediately notify your local Animal Health office.

THE RISK TO YOUR ANIMALS

Avian influenza (AI), commonly known as ‘bird flu’ is a highly contagious viral disease affecting the respiratory, digestive and/or nervous system of many species of birds. It is a disease of birds, not humans, although people and other mammals can become infected they rarely are.

AI is not an air-borne disease, but is spread by movement of infected birds or contact with secretions, and in particular faeces, either directly or through contaminated objects, clothes or vehicles.

There are many strains of AI viruses which vary in their ability to cause disease (pathogenicity). They are categorized as either highly pathogenic avian influenza viruses (HPAI) or low pathogenic (LPAI).
LPAI does not always cause obvious disease in birds. It is thought that influenza viruses circulate freely in the global wildfowl population and cases of LPAI disease are not uncommon in Europe. Certain sub-strains of LPAI - type H5 and H7 viruses - may mutate and become highly pathogenic.

HPAI can spread easily and quickly between birds in poultry populations and cause severe disease, with a high death rate. In rare cases, some HPAI strains have lead to severe disease and deaths in people where infection has resulted from close contact with infected birds.

The highly pathogenic H5N1 strain of the virus became known in South East Asia in 2004, and has led to the destruction of millions of birds. A series of H5N1 outbreaks in domestic and wild birds have occurred across Europe, including Great Britain, but with early detection and effective control these were eradicated quickly.

The latest information on the most recent cases in Great Britain can be found on the Defra website.

HOW TO RECOGNISE THE DISEASE

What to look for in birds

Typically HPAI presents suddenly with affected birds showing oedema (swelling) of the head, cyanosis (blue discolouration) of the comb and wattles (neck and throat area), dullness, a loss of appetite, respiratory distress, diarrhoea and a drop in egg production.
Birds can be infected with LPAI without showing any signs of disease. However, there can be considerable variation in the clinical picture and severity of the disease associated with the type of birds infected and whether birds are also suffering from other diseases.

Photographs of clinical signs of avian influenza are available from the Defra website.

Avian influenza in other animals

Whilst other species of animals have been known to contract avian influenza it is very rare. For more information on the disease in cats, dogs and other pets, visit the Defra website.

REDUCING THE RISK OF DISEASE

Avian influenza may be transmitted by:

  • Contact between infected wild birds and domesticated birds
  • Direct contact with secretions from infected birds, especially faeces
  • Contaminated vehicles, equipment, personnel, clothing, water or feed.

It is vital that all bird keepers in the UK continue to practice the highest levels of biosecurity and be vigilant for any signs of disease. If you are concerned about the health of your birds you should seek advice from your veterinary surgeon. If you suspect that your birds have avian influenza, you should report it to your local Animal Health Office immediately.

Kept birds

It is important that those keeping birds, whether farmed or as pets, should:

  • Review and assess the risk of disease to your birds with your own vet
  • Plan how you will isolate free range birds if there is a need to separate them from wild birds
  • Feed and water birds in doors where possible to reduce mixing between kept and wild birds
  • Practice good biosecurity
  • Be vigilant and monitor your birds regularly for signs of disease.

For more detailed information on the action bird keepers can take see the Defra advice leaflet Biosecurity and preventing disease: peace of mind, a healthier flock and a more viable business (PDF 85 KB).

See also our page biosecurity information for advice on how to help prevent the spread of disease, and improve farm efficiency.

More specific advice is also available:

Separating kept and wild birds

Birds kept in your home

Zoological and other collections

  • For biosecurity advice for zoological and other collections of birds visits the Defra website.

Bird gatherings

  • For advice on biosecurity at bird gatherings (markets, shows and fairs) see our Biosecurity page.

Game birds

Dealing with dead birds

Wild birds

Wild birds can carry several diseases that are infectious to people. For advice and what to do if you find dead wild birds please visit the Defra website.

REDUCING THE IMPACT OF DISEASE

Great Britain poultry register

The Great Britain Poultry Register gathers important information about certain species of birds held on premises in Great Britain in order to help reduce the impact of a disease outbreak.

You are required to register your premises if you have a flock of 50 or more birds. You are encouraged to voluntarily register flocks of less than 50 birds. New registrations must be notified within one month of the birds being acquired. It is also necessary that the register of any significant changes to your holding. This should be done as soon as possible and in any event within one month of the changes happening.

Advice for pig owners

Specific advice for pig owners in the event of an avian influenza outbreak can be found on the Defra website.

Advice for those working with birds suspected of being infected

Advice on avoiding the risk of infection when working with poultry suspected of having highly pathogenic avian influenza can be found on the Defra information leaflet 'Avoiding the risk of infection when working with Poultry that is suspected of having highly pathogenic avian influenza' (PDF 134kb).

Legislation

Page last modified: 25 July, 2011