Strangles is an infection caused by the bacteria Streptococcus equi equi. It is a highly contagious disease seen in horses, donkeys, and mules. Although young horses are typically affected, any age group can become sick. Typically the horse develops a fever (high temperature, >38.3*C) and swollen lymph nodes which abscess and rupture. The purulent material (creamy yellow discharge) in strangles abscesses and from the nose contains very high numbers of the bacteria. The infection spreads by direct horse-to-horse contact or by humans, tack, drinking troughs, fences, and from the environment contaminated with the infectious discharge. Vaccination is recommended to either prevent the disease or at least reduce its severity and duration.
Vaccines against strangles are highly recommended. Around 50% of vaccinated horses will still develop a milder form of strangles after exposure. The vaccine is an injection into the muscle and can be given alone or combined with tetanus (2-in-1).
Initially, a course of 3 vaccines should be given, each 2 weeks apart. This may also be required in horses that are overdue for vaccination. Immunity to infection should be present 2 weeks after the final vaccine. Recommendations for booster vaccination are at least every 12 months and every 6 months in horses that travel and contact other horses regularly.
There are some risks associated with vaccination, including very rare cases of purpura haemorrhagica. However, the risk of purpura haemorrhagica is much greater in non-vaccinated horses that contract strangles.
Horses can have colic for many reasons, so recommendations for management may vary. If you have any questions or concerns with your colicky horse, please get in touch with us.