Well, I believe I would start by talking to my vet and getting his/her input, then do some research according to what I wanted to do with my herd and make my decision. For example, if I were raising cow/calf pairs I would vaccinate for brucellosis and see what the numbers were for the incidence of lepto and vibrio and go from there, given the weather in Florida you probably don't have to worry about scourguarding, but not certain on that. Also not certain about the number of cases of blackleg, etc. Only the vet or a well-experienced fellow cattleperson can tell you that. Are you catching my drift? The diseases we face here in Wyoming are not necessarily going to be consistent with what you face there in Florida. Also, just because it's a disease known to cattle doesn't necessarily mean it's likely to happen in your neck of the woods - only your vet or a trusted, experienced cattleman can tell you that. I hope this helps.