Diseased Bird: One-legged Curve-billed Thrasher

In Colorado,Curve-billed Thrashers are only seen in the southeast part of this state, & I am lucky to have resident Curve-billed Thrashers for 10 years. This photo was taken September 18, 2020 in my front yard. I don’t know how his leg was injured, but I have seen two huge cats in my yard four times this past summer. I have presumably seen him, with his leg completely gone during my FeederWatch 20-2021 many times, but he will show up when all other birds have flown off. He likes to perch on my garage roof, above the front yard feeding area to sun, and won’t fly off when I am outside with my camera! He is the first and last bird to feed at my feeding area.