I had a grey with sever rear leg spasms at one point. It was about 3-4 months old. It couldn’t even use its rear legs at one point. I separated him and started coating the crickets with calcium powder (Fluker’s calcium with vitamin D3 powder). He was the biggest frog, and the second biggest frog started showing the same symptoms a week later. After a month the first frog was doing better, and the second frog wasn’t showing anymore symptoms. The biggest frog completely recovered after about 2 to 3 months and was returned with the others. These were growing frogs, but calcium coated crickets worked wonders. They are close to adult size now and doing well. I may have grown them too quickly as they are only 8 months old.
