Strangles in horses is very contagious. Here are a few links on Strangles. The best way to protect your horse is to vaccinate your whole herd every year.
http://www.omafra.gov.on.ca/english/liv ... 03-037.htm
http://www.horsecouncil.org.au/_Upload/ ... mation.pdf
http://evrp.lsu.edu/healthtips/Strangles.htm
http://www.ag.ndsu.edu/pubs/ansci/horse/v541w.htm
http://www.cyberhorse.net.au/csl/strangles.htm
http://www.myhorse.com/health/seasonal/ ... gles_cycle
