This disease strikes terror into the heart of horse owners, possibly because of its emotive name. Although it’s true that horses can die from strangles, it’s very unusual for this to happen in the UK. More often one sees a profuse nasal discharge and sore, enlarged lymph glands just inside the bone of the lower jaw and throat. The horse may develop a fever, loss of appetite, depression and a cough, or less severe signs such as dullness. Very occasionally, serious complications cause further abscess growth, known colloquially as ‘bastard strangles’.
Up to 10% of horses may recover and appear normal but remain infected. These horses harbour the bacteria within the guttural pouches of the throat; they can infect other horses.
Strangles is caused by a bacterium called streptococcus equi – or ‘strep equi’. It is extremely contagious and can affect horses of any age. Infection can be spread through the air and carried on clothing, hands, grooming equipment and even on the coats of dogs and cats.
Can we protect our horses against strangles?
Prevention is most definitely better than cure; keep your horse away from infected horses and material. There is a strangles vaccine in the UK which can reduce clinical signs, though it’s not widely used and is actually out of stock at present.
A policy of openness is vital – after all, it’s not neglect but bad luck that causes infection.
What should we do when an outbreak is confirmed?
Once an outbreak is confirmed, managers of equine premises should stop all movement on or off the yard, with horses which have been in contact with infected animals kept separate from those who haven’t, as well as those displaying signs of infection – isolation is key when it comes to preventing the spread of strangles. It’s also important to take regular temperatures to check infection hasn’t occurred – ask your vet if you’re not sure how to do this. Changing your own clothes after dealing with infected animals is also important. You should also disinfect the stables thoroughly once the infection is cleared.
An outbreak of Strangles is an expensive and time-consuming event for all parties but careful management, good communication and paying heed to your vet’s advice will all cut down on both suffering and expense.
Dr Mark Sanderson BVM&S MRCVS
Severn Edge Veterinary Group