Cytologic findings of tracheobronchial aspirates from 66 thoroughbred racehorses.

The research focuses on the examination of tracheobronchial aspirates in 66 healthy Thoroughbred racehorses, identifying the presence of numerous cells and elements suggesting widespread inflammatory airway disease.

Analysis of Tracheobronchial Aspirates

• In order to understand the health of the respiratory system of Thoroughbred racehorses, tracheobronchial aspirates were studied. These samples were collected from 66 horses that were deemed healthy and undergoing training at the same racing track. The objective of the research was to deduce patterns that may suggest health conditions not immediately apparent.

Findings

• The study found that 27% of the horses had greater than 20% neutrophils in their aspirate. Neutrophils are a type of white blood cell; having more than 20% of these in the aspirate often indicates an inflammatory response in horses.
• Also found were eosinophils, mast cells, giant cells, and Curschmann’s spirals of mucus. Presence of these was 94%, 83%, 65%, and 42% respectively, indicating different degrees of potential inflammation or immune responses.

Presence of Hemosiderophages and Fungal Elements

• 86% of the horses had evidence of hemosiderophages, a type of cell that eats iron. Half of these horses had previous confirmation of exercise-induced pulmonary hemorrhage. This suggests that this health issue, while known in some horses, may be more prevalent than was previously identified.
• Interestingly, while fungal elements were detected in the lungs of 70% of the horses, bacteria were found in only 3% of the horses.

Conclusion

• Based on the findings, the authors concluded that inflammatory airway disease is likely widespread among racing Thoroughbred population. This may not have been apparent without the deep analysis provided through examination of tracheobronchial aspirates.