Adding to the already existing challenges around daily life in 2021, the current avian inﬂuenza (AI) outbreak is putting an extra strain on those that keep birds, both privately and commercially. The current AI outbreak is of several highly pathogenic strains that have caused disease events in the UK previously, most recently in the winter of 2016/2017 and in 2018. AI is a notiﬁable disease, which means that the animal’s keeper is legally obligated to contact the Animal and Plant Health Agency (APHA) if the disease is suspected, so that APHA veterinary personnel can enter the premises and perform a full enquiry. Restrictions will be placed on the premises and samples taken. A temporary control zone may be introduced around the premises too. For keepers of chickens, ducks, geese, turkeys, meat pigeons, partridge, quail, guinea fowl and pheasants, ﬂocks of 50 birds or over must be registered with the Department for Environment, Food and Rural Affairs (Defra). Defra recommends that all keepers of such birds register their ﬂock (no matter how small) so that owners can be informed of AI outbreaks as and when they occur and precautions taken accordingly to keep all birds safe.
Any bird keeper with concerns about AI in their ﬂock must contact their local veterinary practice immediately. All bird keepers need to be vigilant to the activities and presence of wild birds and prevent mixing of wild birds with the birds housed under their care. The spread of AI seen this year and in previous years has been predominantly by wildfowl (ducks, geese and swans) but also by gulls, herons and egrets, and birds of prey (Figure 1). Three strains of highly pathogenic avian inﬂuenza (HPAI) have been identiﬁed in birds during winter 2020/2021: HPAI H5N5, HPAI H5N1 and HPAI H5N8. These HPAI strains are characterised by sudden mortality in the infected individual bird.
Backyard chickens and ducks need extra attention from their keeper during this difﬁcult time. Biosecurity measures are essential to keep birds healthy and keep the chance of AI infection as low as possible (Figures 2 and 3), and on 11 November 2020, Defra announced an avian inﬂuenza prevention zone (AIPZ) for the whole of England. This means that all keepers of all birds (poultry or non-poultry) that are housed outside should be brought under cover or, if this is not possible or cannot be performed for welfare reasons, food and water must be kept separate from wild birds at all times. Failure to comply with these protective housing requirements contravenes the law, which is enforced by the local authority.
The key signs of HPAI are dependent upon the species of bird infected and the main carriers (ducks, geese and swans) often present with minimal clinical signs. Unexpected death is, unfortunately, one of the ﬁrst noticeable signs of infection. Key symptoms to be observant of are: a gaping beak, coughing and/or sneezing and rattling breath (all indicative of respiratory distress), a loss of appetite, diarrhoea and a reduction in eggs being laid (in chickens kept for eggs). Birds can also present with a swollen head and blue discoloration of the throat and neck. Consider the use of footbaths (essential for keepers of 50 or more birds) when entering and leaving the area where birds are housed. Footbaths are also recommended if multiple enclosures are maintained that house different species of bird.
Defra has published extensive guidance on implementing biosecurity measures, including a biosecurity self-assessment checklist that can be used to evaluate the strength of current biosecurity measures. Key biosecurity measures are: observation of domestic/captive birds, seeking veterinary attention as soon as something unusual is noted, separation of domestic/captive birds from wild birds and cleaning and disinfection of all bowls, tools, equipment and vehicles that the domestic/captive birds are in contact with.
The behaviour and welfare of birds housed indoors is a key consideration. It is essential that birds, which are now likely to be housed in more restricted conditions, are kept occupied to prevent boredom, unwanted aggression between individuals and the development of behavioural abnormalities (eg over preening or feather picking). Enrichment options can include the use of straw bales that allow the birds to peck or scratch through them, hanging leafy greens for foraging opportunities and areas of deep substrate (such as bark chips) for digging and dustbathing.
For waterfowl being housed inside, it is important that birds have access to bathing water to ensure that the birds keep their plumage in good condition and well oiled. Ducks and geese at a minimum must be able to fully submerge their heads under water to keep their eyes clean and healthy and so they can scoop water over their feathers for preening. Always make sure that the birds are kept on clean substrate that reduces the potential of bumblefoot developing.
Observe birds closely to make sure that social hierarchies do not prevent some lower ranking individuals from accessing food and water or important resources (such as perching).
The Defra website provides excellent resources on the current AI situation including the avian inﬂuenza prevention zone and contact details for reporting cases