Foot swelling is mainly caused by virus. The yellowing of the corners of the mouth and the yellowing of the tip of the tail, including the "excessive internal heat" in the corners of the mouth, are all caused by viruses and are called "herpes simplex" in the onset of the corners of the mouth. If the virus reaches the genitals, it is a sexually transmitted disease. People who have studied medicine should know that I am right.
Some birds have low resistance and are easily attacked by viruses, and then their resistance drops, bacteria attack again, and coccidia attack in their bodies. Under the attack of many parties, coupled with the unsatisfactory sanitation of the captive environment, it is easy to swollen feet. After the foot is swollen, there are many drugs that can be treated, such as painting and spraying. I have used everything, including iodine and 84 disinfectant. The calamine lotion used to treat "herpes zoster" is the fastest. Anyway, everyone has his own method.
I have also used Vidanin spray once a day, and I will feed some cucumbers every day, about 10 days. You can try.