Avian pox is caused by a virus and over the last few years we have seen sporadic cases of the disease in British garden birds.
- Please note: avian pox is a different disease to avian influenza.
Although many of the sporadic cases have involved birds like Wood Pigeon and Dunnock, we have seen an increasing number of cases during late summer in Great Tits.
Pathology & disease spread
Affected birds develop warty or tumour-like growths, often on the head (around the eyes or beak), wings or legs. The growths can become very large and may impede the bird by, for example, restricting vision. This can lead to increased risk of predation or of secondary infection. The growths are usually grey, red, pink or yellow in colour.
Transmission appears to be by one of three routes: namely, biting insects (e.g. mosquitoes), bird to bird contact or indirect contact, the latter through contaminated bird feeders or feeding surfaces. The virus is relatively resistant and can persist for long periods outside of the host. Avian poxes do not appear to be infectious to humans or other mammals.
What you can do
A few simple precautions will help limit the spread of avian pox in gardens and on feeders.
- Clean and disinfect feeders and feeding sites regularly. Suitable disinfectants that can be used include a weak solution of domestic bleach (5% sodium hypochlorite) or other specially-designed commercial products.
- Always rinse feeders thoroughly and air-dry before re-use.
- Rotate positions of feeders in the garden to prevent the build up of contamination in any one area of ground below the feeders.
- Empty and air-dry any bird baths on a daily basis.
- If you wish to report finding dead garden birds, or signs of disease in garden birds, you can do so through Garden Wildlife Health, our online reporting system. Remove feeders for at least two weeks if you see a diseased or dead bird in your garden.
- Avian pox is a different diesease to avian influenza. Please see our separate page for additional health and safety risks relating to avian influenza.
BTO Data Reports
Our reports provide rigorous scientific information to inform Environmental Impact Assessments in the UK.
BTO is dedicated to tackling the challenge of avian influenza. Learn about the disease, its impact on our wild birds and BTO's efforts to mitigate its impacts.