Background: Strangles is an equine bacterial infection caused by Streptococcus equi subs. equi. It affects the upper respiratory tract of horses and is characterised by abscessation of the lymph nodes. Due to its rapid spread, the presence of asymptomatic carriers and its ability to cause considerable economic damage, strangles represents a major health concern for equids. Serological tools are useful to confirm an outbreak after PCR testing, to assist in sanitary management, and to assess the risk of haemorrhagic purpura. Objectives: To evaluate the performance of a new double antigen ELISA1 for strangles. Study design: Assay validation. Methods: Positive, negative, and asymptomatic horses' samples collected between 2014 and 2023 were tested and correlated to PCR and bacteriology results when available. Samples tested were from 5 origins (i) a first outbreak in Normandy included 22 horses, symptomatic or not that were sampled during clinical signs and two weeks later, (ii) a second outbreak in Lyon where 24 horses were sampled, (iii) 464 sera from a longitudinal study performed in France by LABEO. For specificity assessment, 159 horses were sampled from Iceland where strangles has never been observed. For exclusivity evaluation, 8 horses from Southern France with respiratory symptoms associated with S. equi subsp. zooepidemicus positive PCR were sampled. Results: Measured specificity of the test was 98.5% (n = 159, CI95%: 95.2%–99.5%). Individual detection rate among infected herds was 77% (n = 74, CI95%: 66.2%–85.1%). The ELISA was negative on samples from horses infected with S. equi subsp. zooepidemicus, meaning good exclusivity. Main limitations: Since all sera were obtained from field infections, the exact date of infection was unknown. Conclusions: Data indicate that the new IDvet ELISA test offers reliable diagnostic performance and is useful for sanitary management of strangles. Key manufacturer: 1 Double antigen ELISA for strangles, IDvet, https://www.innovative-diagnostics.com. Ethical animal research: The authors attest that ethics committee oversight is not required in their institute. Informed consent: Owners gave consent for their animals' inclusion. Competing interests: AC, OM, RB, KK and PP are employees of IDVet. Source(s) of funding: IDvet.