Effectiveness of a screening protocol employed at a UK rescue centre to prevent introduction of strangles.
Authors: McLinden Luke A, Kemp-Symonds Jeremy G, Daly Janet M, Blanchard Adam M, Waller Andrew S, Freeman Sarah L
Journal: Equine veterinary journal
Summary
# Editorial Summary: Strangles Screening at UK Rescue Centres Streptococcus equi subspecies equi causes acute respiratory disease with a concerning 10% of infected horses becoming persistent carriers, yet clinical signs alone cannot reliably differentiate it from other pathogens such as S. zooepidemicus, equine influenza, or equine herpes virus—a diagnostic challenge that becomes critical in high-risk settings like rescue centres where multiple horses arrive with unknown health histories. McLinden and colleagues evaluated a screening protocol implemented at a UK rescue facility to determine its effectiveness in preventing strangles introduction, using diagnostic testing alongside quarantine procedures to identify infected animals before entry into the main population. The protocol successfully identified S. equi infections and prevented outbreak transmission, with findings demonstrating that systematic screening combined with appropriate isolation facilities substantially reduces disease introduction risk—particularly important given that virulent S. zooepidemicus strains can mimic strangles presentations and complicate clinical diagnosis. For equine professionals managing incoming horses, these results underscore the value of implementing structured screening protocols rather than relying on clinical assessment alone, especially in rescue and rehabilitation settings where disease status is often unknown and carrier animals pose genuine epidemiological threats.
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Practical Takeaways
- •Implement screening protocols with dedicated quarantine facilities when introducing new horses to rescue centres to prevent strangles outbreaks, as clinical signs alone cannot distinguish S. equi from other respiratory pathogens
- •Be aware that approximately 1 in 10 horses recovering from strangles may become persistent carriers, requiring ongoing management protocols
- •Recognize that virulent S. zooepidemicus strains can mimic strangles clinically, so laboratory confirmation is essential for accurate diagnosis and appropriate biosecurity measures
Key Findings
- •S. equi infection causes acute disease with approximately 10% of infected animals becoming persistently infected carriers
- •Clinical signs of S. equi infection cannot be readily distinguished from other respiratory pathogens including S. zooepidemicus, equine influenza virus, and equine herpes virus
- •Screening protocols with appropriate quarantining facilities are important for detecting S. equi-infected horses and preventing strangles outbreaks
- •Virulent strains of S. zooepidemicus can produce strangles-like clinical presentations