It affects horses, donkeys and ponies of all ages, breed and sex. The bacteria often infect the lymph nodes around the jaw, causing them to become swollen. In severe cases they can become so swollen that horses struggle to breathe properly, hence the name 'Strangles'.

What does strangles do to a horse?

Strangles is a highly contagious disease of the equine upper respiratory tract caused by the bacterium Streptococcus equi subspecies equi (S. equi). The bacteria cross mucous membranes in the nose and mouth to infect lymph nodes where they cause abscesses that can eventually rupture.

How long does the strangles virus live?

Strangles can stay active in water buckets and moist areas for four to six weeks, and the bacteria can survive for about one to three days in drier areas such as on fencing or in soil.