The incubation time for Strangles is anywhere from three days to two weeks. The first sign of sickness will be a fever spike, followed in a few days by nasal discharge. The horse is likely to develop a cough. Eventually, the lymph nodes will rupture, causing the external sores.
Treatment for Strangles includes anti-inflammatory medications, as well as fever-reducing medications. The abscesses should be allowed to drain, and should be flushed with diluted iodine several times a day. Due to Strangles being an infectious disease, horses with clinical signs should be quarantined.
Antibiotics are generally contra-indicated as they slow the progress (and therefore healing) of any abscesses.