Research underpinning the commercialised blood test for diagnosing small redworm (cyathostomin) infections in horses has been published in the International Journal of Parasitology.
The paper describes the research undertaken to define the final format of the test which was developed at the Moredun Research Institute and commercialised by Austin Davis Biologics in September 2019.
A new antigen was discovered to be important in accurately identifying cyathostomin burdens when combined with previously identified cyathostomin antigens in an enzyme linked immunosorbent assay (ELISA) detecting cyathostomin-specific IgG(T) antibodies in horse serum. This three-antigen cocktail was identified as being the most suitable for a commercial test to detect all stages of the small redworm life cycle, including the all-important encysted larval phase. Until now it has not been possible to test for encysted small redworm as faecal egg counts only detect the presence of egg laying adult worms.
Small redworms are the most common gastrointestinal parasites to infect horses. When horses harbour a large burden of encysted larvae that emerge en masse from the intestinal wall clinical symptoms develop, such as diarrhoea and colic, which can be fatal (larval cyathostominosis). Moxidectin is the only de-wormer capable of eliminating these encysted stages for which worm resistance is not known to be widespread. To protect the effectiveness of this de-wormer, targeted treatment programmes are required to ensure that the drug is only administered when it is really needed.
Blood test results are intended to complete a “diagnostic profile” for veterinarians along with historical faecal egg count results and assessment of grazing management to enable decisions to treat/not treat an individual horse or group.
Professor Jacqui Matthews, Chief Technology Officer at Roslin Technologies and Inventor of the test, said, “This research paper describes the selection of antigens that provide coverage for detecting the commonest cyathostomin species found globally“.
Dr Corrine Austin, Director at Austin Davis Biologics, commented, “Publication of this research is important as it provides veterinarians with additional evidence of the commercial test’s accuracy. Following on from this published research, we conducted additional validation and optimisation of the test for use on robotic systems.”
Dr Stewart Burgess, Principal Investigator at the Moredun Research Institute commented, “The availability of the test greatly benefits evidence-based worm control in horses and fills an important gap in the diagnostic toolbox for equine veterinarians”.