I've always been told to not lance an abscess - have it removed whole if possible and send in for testing. That reduces the spread of the contagion.
Just because lancing is listed as a method of treatment, does not mean it minimizes the transmittance of the disease - in the case of a messy abscess, being sure to sanitize the wound, area around the wound, clean up all 'touched' items, and be sure that no future ooze will come from the opened abscess means that it could very well still spread it.
I have never once seen that you can't own animals for 50 years. However, there is truth to it infecting people, horses, rabbits, cows - maybe other animals. I just opened the Merck VM and I founds something interesting - horses get a the same disease, but slightly different bacteria. Cows get a mix of horse/goat types, goats get a specific kind as well. Fascinating. At least now I don't have to worry about horses bringing it into goat herds, if I ever got a horse. Of course, a sale barn animal could still carry it on hooves. And cows still aren't safe.
I have always heard that it can stay in the soil for up to 10 years. Since it is non-endospore forming that is a difficult trick, IMO. The more I read books like the Merck Vet manual it seems that it lives just a few years. This is variable with exposure amounts (direct sun, dry climate, or 'dilution' by a lot of rainfall obviously will reduce viability/concentration of bacteriums) so keeping a clean pen and areas helps a lot. If I ever had to deal with it, I would probably act as though it lived in the soil for at least a few years.
(Merck Vet manual - says months alive in soil/bedding)
http://www.merckvetmanual.com/mvm/in...ulosis%2cgoats
(Goat Medicine - says up to 30 months in soil). It also scares me with vertical transmission - dam to kid in utero - and also through biting flies.
Goat Medicine - pg 67
As for meat carcasses, last I HEARD was that if 2 abscesses or more are found in the carcass, the carcass is discarded and cannot be used for consumption. I just went looking and found this article saying visceral abscesses (internal) condemn the carcass:
http://goat-link.com/content/view/101/96/
A little more official (Goat medicine google e-book) saying that visceral abscesses can mark down or condemn a carcass:
Goat Medicine