Strangles

Have you ever had a conversation about strangles? No? Many horse owners haven’t, which is one of the reasons it has thrived – along with the myths, misunderstandings and silence that surround this unpleasant disease. But if we’re to stand a chance of reducing the UK’s 600 annual outbreaks we all need to share information and support those affected.

What is strangles?

Infection begins when Streptococcus equi bacteria enter a horse’s respiratory system and travel to lymph nodes in his head. It usually takes 2–14 days for an infected horse to become unwell, but occasionally longer – one patient in Redwings’ outbreak took 21 days to develop the disease.

The first sign is usually a fever (a temperature above 38.5°C). At this stage, the horse is unlikely to be infectious, but once nasal discharge, swollen glands or a cough develop, he’ll probably be spreading bacteria. This means it’s important not to wait for visible signs. By monitoring your horse and checking his temperature regularly, particularly after mixing with other horses, you have the best chance of spotting infection early and containing it.

We’re increasingly aware of horses who test positive but only show mild symptoms, while still being infectious. These cases can be easy to overlook. And while most horses recover in a few weeks, the disease is fatal in 1–2% of cases. Younger or older equines, and those with health conditions, are most vulnerable, but any horse can fall victim.

How do horses get strangles?

Strangles is highly contagious, meaning horses without immunity will almost certainly become ill if exposed. However, unlike conditions such as equine flu, strangles isn’t airborne, so it’s easier to stop it spreading.

Direct interaction between horses is the biggest risk, particularly nose-to-nose contact. But horses can also become infected indirectly through contact with contaminated items. This could be anything from stabling or transport to buckets, wheelbarrows or hands.

Strangles can survive in the environment, too. In hot, dry conditions bacteria are unlikely to last for more than three days. However, in cool, damp conditions Streptococcus equi is more resilient. One study found bacteria survived on a boot sole for three weeks, and in a damp bucket for almost five weeks. Water tanks are particularly high risk, with bacteria still present after six weeks.

Find out more about strangles and how to manage the risks in June Horse&Rider, on sale 29 April.