Black Diamond, maybe you're talking about something different. Foot rot, as I know it, is an infection in the foot and possibly the lower leg. Like any infection, it can kill an animal if left untreated. I don't have any idea how you would "cut away" the infected part since you would be hacking away at skin, bone and muscle tissue. Our cattle are on irrigated pastures all summer so we do get a case or two a year. We treat with antibiotics as soon as possible. If you catch it early and are in a position where you can treat the animal easily, start with LA200. There are better - but more expensive -alternatives as mentioned above.