Strangles; Strep life cycle
Here is an excerpt from this link http://www.omafra.gov.on.ca/english/livestock/horses/facts/03-037.htm#prevent about that: Under optimal conditions, the bacteria can survive probably 6–8 weeks in the environment. Jorm (1991) has shown that S. equi survived for 63 days on wood at 2°C and for 48 days on glass or wood at 20°C. (6) The organism is readily killed by heat (60°C) or disinfectants (particularly povidone iodine, chlorhexidine). Rest contaminated pasture areas for 4 weeks, since the natural antibacterial effects of drying and of ultraviolet light will kill the organism.You may want to consider vaccinating any horses before they come to the barn as a preventative and be sure to keep them isolated from the rest of the herd for at least 2-3 weeks.Hope this helps!