Avian Pox
Avian Pox is a relatively new (and emerging) disease in the UK, which seems to be increasingly identified in garden birds. The disease is caused by an AviPox virus - a thick walled virus. The virus causes two types of disease – a dry ‘cutaneous’ (skin) form which stimulates excessive skin growth and nodular warty lesions. This type of pox infection is most commonly seen in our garden birds. The other ‘wet’ form of the disease, is more commonly seen in domestic chickens and turkeys, where the virus infects the mucous membranes of the digestive and respiratory tracts. This electron micrograph of a pox virus, shows how thick walled the virus is. This thick wall enables pox viruses to be extremely resistant to environmental factors (such as disinfectants), and the virus survives and multiplies really well in dry conditions. This is why Pox lesions are seen more commonly in the summer months than the winter.


It would seem that currently Great Tits are more predisposed to Avian Pox infection than other UK garden birds however lesions have been recognised in Dunnocks, Wood Pigeons, Blue Tits, and I have also seen Blackbirds with Pox lesions.

In most other species, the virus will cause mild lesions, usually on the featherless areas - the legs and around the eyes and beak. Often seen as bald/scaly patches, or pinky/grey plaques, these birds often mount an immune response to the virus and survive the infection.

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