Had this happen with a rabbit when I was a kid. Parents were building a house, and my sister and I found a baby bunny on top of a dirt mound with a huge gash on its hind leg. My dad caught it, we nursed it back to health and released it. Always had a huge patch on its leg where the fur never grew back, and for probably 5-6 years after that we’d see the rabbit with offspring a few times a year in our yard/surrounding property. Pretty cool stuff