Comparison of respiratory secretion cytology and pulmonary histology in horses.

This research article explores the comparison between respiratory secretion cytology and pulmonary histology in horses. The study analyzed respiratory secretions from horses before and after they were euthanized and classified the horses according to lung histology. The findings indicated a correlation between specific lung conditions and changes in the cellular composition of respiratory secretions.

Study Methodology

• The study involved respiratory secretions (RS) collected from a total of 109 horses both before and after they were euthanized.
• The histological diagnosis of the lungs from the horses was used to categorize them into specific groups, which included horses with normal lungs (serving as the control group) and horses with various lung diseases.

Group Analysis and Findings

• The researchers found that there were significantly more neutrophils in the RS of horses with mild, moderate, and severe chronic small airway disease and interstitial pneumonia compared to the control horses.
• Horses with severe chronic small airway disease also had significantly more lymphocytes and fewer ciliated columnar epithelial cells in their RS than control horses.
• The study also revealed that significantly more eosinophils were present in the RS of horses with pulmonary eosinophilic infiltration than in those of control horses.

Individual Analysis and Findings

• When looking at individual horses, all those with moderate and severe chronic small airway disease as well as those with pulmonary hemorrhage had an RS cytology that varied from the control horses.
• However, some horses with mild chronic small airway disease, pulmonary eosinophilic infiltration, and interstitial pneumonia did not show differences in their RS cytology compared to the control horses.

Research Conclusion

• The findings suggest a correlation between the cytology of respiratory secretions and various histological lung conditions in horses.
• This information could potentially be used to predict lung disease in horses based on the cellular composition of their respiratory secretions, although some exceptions were found.