From the October 2017 General Meeting:

Local veterinarian Ruth Sobeck DVM shared about 2 local recent cases of Streptococcus equi ssp. equi (Strangles) and Streptococcus equi ssp. zooepidemicus in horses.
What to look for: nasal discharge and pus oozing from abcesses (both infectious), swollen face and/or neck glands/guteral pouch, and fever above 101 degrees. Horses can shed bacteria for years.
She kindly and thoroughly went over all sorts of scenerios at length on vaccinating for Strangles, titters, and rare purpura hemorrhagica (complications from vaccinating during outbreak when exposed horse’s blood levels already elevated levels of Strep antibodies).
See link below for ACVIM statement on Strangles. 3 pages of facts and to learn more 12 pages of scientific info.
ACVIM – Strangles Info