More details on methods for prevention of introduction of strangles onto equine premises are available in the ‘Strategy to eradicate and prevent Strangles (STEPS)’ document here.
Ideally, all horses entering any stud or stable premises should be quarantined for a period of 3-4 weeks and monitored closely for any clinical signs of an infectious disease, including daily temperature monitoring, particularly in the period immediately after arrival. Any horse that develops a nasal discharge or other signs consistent with strangles should be isolated and tested for the presence of, or exposure to, S. equi.
The strangles blood test can be used to identify horses that have elevated antibody responses to S. equi and are therefore likely to have been exposed to this pathogen in the recent past, enabling the identification of potentially infectious animals before or immediately after movement. A further blood test at the end of the quarantine process can be used to identify animals that may have seroconverted since their arrival, consistent with recent exposure to S. equi. It is recommended that any quarantine batches of horses that include seropositive animals, as well as those seroconverting whilst in quarantine, not be released until their infectious status has been shown to be negative for presence of S. equi (see Diagnosis below).
Veterinary advice should be sought to determine whether use of vaccination may be appropriate on the basis of a specific risk assessment and bearing in mind that the modified-live vaccine may trigger positive results in diagnostic tests for strangles. See Appendix 8 for information on available vaccines.