Horse Trust Blood Test Identifies Horses Infected with Strangles
A new blood test to diagnose strangles is being developed as a result of funding from The Horse Trust. The process will provide a more effective, reliable and less invasive method of diagnosis than the current test.In order to validate the blood test, over 1,000 horses naturally infected with strangles will be surveyed over a three year period. The work will be carried out by the Animal Health Trust and will be the largest ever survey of strangles.
Current testing involves taking a naso-pharyngeal swab - a swab is inserted up the animal's nose to the back of the throat. However, because the casual bacterium, Streptococcus equi, is shed intermittently this may not detect all infected animals.
The new blood test, funded by The Horse Trust, will quantify a horse's immune response towards Streptococcus equi, whether or not the bacterium has been shed at that precise moment in time making the blood test more effective and less intrusive.
"We are delighted that the funds we have devoted to developing a diagnostic tool for strangles have had such a positive result," said Paul Jepson, chief executive and resident veterinarian of The Horse Trust. "A reliable test using a simple blood sample is a major step forward and this work will have a huge impact on horse welfare if it enables owners to identify the disease and initiate effective antibiotic treatment."
"Our aim is to identify potential carriers and then investigate these further by guttural pouch endoscopy and lavage," says Jeremy Kemp-Symonds of The Animal Health Trust. "Sometimes you can see obvious pus or chondroids in the guttural pouch; on other occasions you can identify Streptococcus equi only on laboratory analysis. However, any of these signs confirm the carrier status."
The good news is that, once diagnosed, carriers can be treated.
"To date we have identified over 30 carriers from 16 strangles outbreaks and are diagnosing more every week." says Mr Kemp-Symonds. "Fortunately, we have successfully treated the vast majority of these already with obvious and immediate benefits for the premises concerned."
Treatment involves washing out the material in the guttural pouch via the endoscope, introducing antibiotics to the guttural pouch and putting the horse on systemic antibiotics.
In the longer-term, the Horst Trust blood test could significantly reduce the occurrence of strangles in the UK by identifying infected horses before they can pass the disease on.
"The prototype test appears to be very good; we are refining and improving it at this stage," said Mr Kemp-Symonds.
In the meantime, owners who suspect their animals may have contracted strangles can take a lead from a large yard which suffered a serious outbreak earlier this year.
Their diligence with biosecurity limited the spread of the disease and the number of animals which became carriers. They self-imposed a movement ban; prevented new horses coming into the yard and controlled the extent of the outbreak by identifying animals with the disease and isolating them, their tack and their handlers from the uninfected horses on the premises.
Post this story to: 
