Gouldian Finch - standing on right leg only - left leg weak
I have a Gouldian finch who began standing only on his right let, holding his left leg up constantly. I checked his nails and they appear to be of normal length. There were no other obvious signs of injury to the left leg or foot. I've noticed that if he attempts to use the left leg/foot to stand/perch he is unable to maintain a grip and occasionally falls backward off the perch. What might be the cause of this?