Temporal clinical exacerbation of summer pasture-associated recurrent airway obstruction and relationship with climate and aeroallergens in horses.

This research study investigates the relationship between environmental conditions, including climate and aeroallergens, and the seasonal worsening of a respiratory condition in horses. It particularly focuses on summer pasture-associated recurrent airway obstruction (SPA-RAO).

Research Methods

• The study involved a total of 29 horses, with 19 of them suffering from SPA-RAO and the remaining 10 not affected by the condition. These could provide comparative and control data.
• All the horses were kept on pasture and observed over a period of three years. This allowed a comprehensive analysis of the respiratory condition and its progression across different seasons.
• The research used a clinical score of respiratory effort to determine the onset and exacerbation of SPA-RAO amidst varying environmental conditions. This included maximum, minimum, and mean temperatures, as well as maximum, minimum, and delta dew-point temperatures, which represent humidity.
• The researchers also evaluated the count of 20 types of fungal spores and 28 types of pollen, considered as aeroallergens, in relation to the clinical condition of the horses.

Research Findings

• The data suggested a relationship between the worsening of SPA-RAO and increases in temperature, dew-point temperature, fungal spores, and grass pollen grains. This suggests that hotter, more humid conditions, coupled with certain environmental allergens, could align with exacerbations of the respiratory condition.
• Specific increases in Basidiospore, Nigrospora, and Curvularia spp. were found to parallel clinical exacerbations, indicating that these specific fungal spore types may be of particular significance.

Research Conclusion

• While the study did not conclusively establish causal relationships between the environmental conditions and the seasonal worsening of SPA-RAO, it did indicate a strong association. The research contributes to the understanding of potential triggers and risk factors for the progression of SPA-RAO in horses.
• The study also left open the question about whether the identified environmental factors are actual aeroallergens which cause the clinical worsening of the disease, signifying further study might be required to corroborate or refute the results.