This may surprise many of us, but according to the Animal Health Trust, there are more than 600 recorded strangles outbreaks in the UK every year on average, and probably many more that go unrecorded.
Any horse is at risk of contracting strangles, but owners can significantly reduce that risk by being aware and proactive, so Horses4Health are happy to get behind Strangles Awareness Week which is once again being organised by Redwings Horse Sanctuary.
What is strangles?
Strangles is caused by a bacteria called Streptococcus equi. It is a common, highly contagious infection of a horse’s upper respiratory tract. It can cause large abscesses to form, make swallowing difficult, restrict breathing and be both painful and distressing for the horse. Persistent infection can develop which results in horses becoming long-term strangles carriers.
Strangles is so contagious that up to 100% of horses with no immunity to the disease will become infected if they come into contact with it. Infection can be passed by direct contact from horse to horse, even if they only touch briefly. But equally important is indirect contact, where bacteria is picked up from stables, field shelters, paddocks, water tanks, yard equipment, transport and people’s hands, boots and clothes. It can feel like it appears out of nowhere, travelling with horses as they move around the country and abroad and often horses are infectious without showing any symptoms so it’s not always straightforward to trace the origin of an outbreak.
Most horses will make a complete recovery from strangles, although the disease often causes considerable suffering to affected horses. However, up to 20% of infected horses are also at risk of serious or life-threatening complications.
Would you know the symptoms if your horse contracted strangles?
Signs of strangles could be any of the following:
• Fever (temperature above 38.5°c/101.3°f)
• Being dull/depressed
• Loss of appetite, difficulty eating or trouble extending the head – signs of a sore throat
• Lymph node swelling under the jaw, behind the jaw or below the ears
• Thick discoloured nasal discharge
• Abscesses under the jaw, behind the jaw or below the ears (these produce thick pus as they burst) • A cough is sometimes present, but is not as common as other signs
It normally takes 3–4 days for signs to develop after a horse has been in contact with strangles bacteria, but there have been cases where it has taken up to 21 days. This is why it is now recommended to keep precautionary isolation in place for three weeks if you are worried your horse may have been put at risk. Check your horse’s temperature twice a day during this period to identify developing infection at the earliest opportunity. Horses will develop fever more quickly than other signs and this usually happens before they start shedding bacteria that can be passed to other horses. This is why monitoring your horse’s temperature after attending events, for example, is so critical to catch infection early and enable you take precautionary action to prevent it spreading.
Some horses show much milder strangles signs. You may only see:
• Mild, short-term fever
• Slight loss of appetite
• Other forms of nasal discharge
These signs are non-specific and you will probably not think of strangles as a possible cause. A horse with mild signs can still pass infection on, however, and needs to be isolated and tested by a vet in the same way as a horse with more debilitating illness. Although these signs may be caused by another health condition, it is always advisable to use isolation as a precaution until you have definitely ruled out strangles.
So how can you protect against strangles?
Good hygiene and isolation practices are the best way to protect any horse from strangles. Vaccines are available, but they should be seen as an option to be used in addition to hygiene and isolation, not instead of them. We cannot yet inoculate horses against strangles as effectively or as easily as we can protect them from equine flu. If you are considering vaccination, ask your vet to assess your horse’s individual situation and activities in order to advise you on current vaccine options.
Information taken from www.redwings.org.uk/strangles where you can find more details and some great downloadable resources.