
Avian Pox is the disease we see the most of here at Kiptopeke. Pox is caused by an avipoxvirus that cause growths on the legs and bare parts on the head. This slow developing disease can be mild to severe. In this case, it is pretty advanced. There is no know treatment for it. The biggest problem we have with it, is that it can be transmitted from bird to bird. So when we catch a bird like this one, we have to alcohol everything that was in contact with that bird, our hands especial, and the bag that held it, is culled out and washed in bleach. Most of the cases we see are

of just a small amount of the warty growths on the toes. This season, there has been about ten cases noted from the Northern Mockingbirds we have been catching. This Gray Catbird has one of the worst cases I have seen at a banding station. Years back, we caught an American Robin here that was just this bad. Both the robin and this catbird were both released unbanded because of the extreme size of the leg, and I don't think that a band would help either one of them out that much. I have also seen pox in Chipping Sparrows here as well.
I recommend googling avian pox and reading up on this disease. Although not a problem for humans, it can be a major cause of mortality in some bird species.