I've got a wild Canada goose that is only able to use one leg. She's been like this for as long as I've known her and that's probably been 3 years. Her leg has atrophied now. Of course she's got a target on her back because she's only able to hop around or fly. She does swim but that's really difficult because she's unable to paddle with the one leg. So she paddles with her good leg and uses her head to kind of thrust her body weight to help move her in the direction she wants to go. She's really impressive in my opinion. Years ago I considered catching and taking her to a waterfowl rescue, but I feel like she'd hate that and I worry they'd euthanize her.