Avian influenza (bird flu): how to spot and report the disease

Advice on what to do if you suspect there is an outbreak of avian influenza.

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Avian influenza

Avian influenza (bird flu) mainly affects birds. It can also affect humans and other mammals. 


Read the latest avian influenza outbreak situation in Scotland, including details of the current disease response plan. 

Avian influenza is a notifiable animal disease. If you suspect any type of avian influenza in poultry or captive birds you must report it immediately by contacting your local Animal and Plant Health Agency (APHA) Field Services Office. Failure to do so is an offence.

Clinical signs

Avian influenza viruses can be classified according to their ability to cause severe disease (pathogenicity) as either highly pathogenic or low pathogenic. The viruses are described by their major antigen determinants, H (for haemagglutinin) and N (neuraminidase). The current strain of concern is a highly pathogenic H5N1.

In birds we are mainly concerned with H5 and H7 subtypes. It is known that the LPAI H5 and H7 virus subtypes can mutate into the highly pathogenic form that causes serious illness and deaths in birds, although in water fowl the disease may not be apparent.

Signs of low pathogenic avian influenza (LPAI)

Typically, infection with LPAI is often difficult to detect, with very few if any clinical signs.

An infected flock might show signs of respiratory distress, diarrhoea, a loss of appetite or a drop in egg production of more than 5%.

If you are suspicious your flock has any form of avian influenza you must contact your local animal health office immediately.

Signs of highly pathogenic avian influenza (HPAI)

Typically this form of the disease presents suddenly, often with very high mortality, with affected birds developing swollen heads, a blue colouration of the comb and wattles, dullness, lack of appetite, respiratory distress, diarrhoea and significant drop in egg production.

However, there can be considerable variation in the clinical picture and severity of the disease. If you are suspicious your flock has any form of avian influenza you must contact your local animal health office immediately.

If you suspect signs of any notifiable diseases, you must immediately notify your Scotland: field service local office at the Animal and Plant Health Agency (APHA). Failure to do so is an offence. Sign up to the APHA Alerts Service to keep up to date with the latest news.

How to unsubscribe from receiving disease alerts

If you have already subscribed to this service from APHA and no longer wish to receive these disease alerts, complete the information on the subscriptions page. You will then have the option to update your subscription.

Human health implications

Some strains of bird flu can pass to humans but this is very rare. It usually requires very close contact between humans and infected birds. Find out more at: bird flu and human health


Email: Animal.Health@gov.scot (however, only report any dead wild bird findings via 03459 33 55 77)

Animal Health and Welfare 
Scottish Government
Agriculture and Rural Economy Directorate
Saughton House

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