We have had a HUGE problem with foot rot this summer! The vet said it was because the really dry ground in SW MO and they step on twigs and cause a crack or sore and the bacteria has a place to grow. If you can get a look at the foot, if you run your finger between the toes and it smells like dead flesh (or thrush in horses), then it is foot rot. We treat with Bio-Mycin 200, 5 ml per 100 pounds. Had a 1600 pound cow this summer and she got 80 CC, sub Q, no more than 12 to 15 per injection site. She was ticked at me when I was done! We had at least 8 cases, and just three weeks ago had a calf get it. We diagnose it by the swollen foot and limping, lower leg. They are usually better within 24 hours, and swelling gone in three days.
We must have the bacteria rampant in our soil, but this is the first year we have had a problem with it. Very expensive when you have so many! Several people have told me that is has been bad this year!