Goldfinch with diseased foot

I'd be interested if any of you bird biologist/veterinarians out there are familiar with this condition and what causes it.

Thanks for your help,

And a close-up.

Very unusual. I've never seen this condition before.

Looks like this bird has scaly leg mites, These mites are most common on budgerigars, where it is found on the cere, the skin around the beak, finches more commonly have their legs and feet affected by these mites. Their legs become scaly and crusty, and their claws become overgrown and cracked. Affected birds often become unable to perch. Looks like the left leg is also affected.

Thank you, June.

I suggest that the foot and facial lesions are more likely the result of avipoxvirus infection. The lesions of Cnemidocoptic mange ("scaly leg and face mite infection) produces a prominant dry, flaky thickening of theepidermis of any unfeathered skin. When it affects the lower leg and foot its thickening quickly obliterates and obscures the scales -which remain well defined in this goldfinch.
Dave Graham
East River, SD