A nationwide surveillance scheme for equine grass sickness in Great Britain: results for the period 2000-2009.
Authors: Wylie C E, Proudman C J, McGorum B C, Newton J R
Journal: Equine veterinary journal
Summary
# Editorial Summary: Equine Grass Sickness Surveillance in Great Britain (2000-2009) Between 2000 and 2009, Wylie and colleagues collated data from the first nationwide surveillance scheme for equine grass sickness (EGS) across Great Britain, documenting 1,410 confirmed cases to establish epidemiological patterns and identify potential risk factors for disease progression and survival outcomes. The research combined retrospective case records with prospective data collected via postal and online questionnaires from 2007 onwards, analysing categorical outcomes using univariable logistic regression to examine associations between case characteristics, EGS form (acute, subacute, or chronic), and survival in chronic cases. Chronic grass sickness (CGS) cases in Scotland demonstrated significantly higher survival rates than those in England and Wales, with approximately 50% of CGS cases surviving overall, suggesting regional variation in disease severity, management protocols, or practitioner expertise rather than inherent case-level differences. Annual case reporting averaged 141 cases nationwide but fluctuated considerably year-on-year, indicating temporal variation in disease incidence that warrants further investigation. These findings provide the foundational epidemiological framework necessary for designing intervention trials—most notably vaccine studies targeting *Clostridium botulinum*—and highlight the importance of standardised case management protocols, particularly in regions showing lower survival rates for chronic presentations.
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Practical Takeaways
- •Equine practitioners in GB should maintain high clinical suspicion for EGS across all regions, with approximately 140 cases expected annually in the surveillance population
- •For horses diagnosed with chronic grass sickness, roughly half can be expected to survive with appropriate care, though survival outcomes may vary by geographic region and quality of veterinary management
- •This surveillance data provides epidemiological baseline information that can guide future preventive strategies, including vaccine development and trials against Clostridium botulinum
Key Findings
- •1,410 EGS cases were documented across Great Britain between 2000-2009, with an average of 141 cases reported annually but with inconsistent year-to-year variation
- •Approximately 50% of chronic grass sickness cases survived overall, with significantly higher survival rates in Scotland compared to other regions of GB
- •EGS affected equids throughout England, Scotland, and Wales, indicating widespread geographic distribution of the disease
- •No significant relationship was found between case details and the category of EGS or outcome among CGS cases in univariable logistic regression analyses