Given his good health and that he lived on 40 acres, with my other two horses and the landowner's Black Angus, it was the last thing I expected.
I would imagine a horse getting Strangles at age 27 might be comparable to a human getting a full blown case of the Mumps. Childhood diseases are much more difficult to get thru for an adult
I absolutely had no way to isolate Sonny; amazingly, my other two horses never got Strangles from being exposed to him. One was 25, the other in her early teens.
This happened in 1987 and I am pretty sure I gave Sonny some sort of oral antibiotic. I don't think that is done today if it stays under the jowels. Yes? No?
I also had something medicated to clean him with twice daily.