Air sampling in the breathing zone of neonatal foals for prediction of subclinical Rhodococcus equi infection.

The study researches the feasibility of using air sampling from the breathing zones of neonatal foals to predict future cases of Rhodococcus equi pneumonia, which is a significant problem in the horse breeding industry but difficult to diagnose early. However, the research found that there was no significant correlation between detecting virulent R. equi in the air samples and subsequent cases of rhodococcal pneumonia, indicating that this method may not be a reliable way of predicting the disease.

Objective of the Study

• The main objective of this study was to investigate whether sampling air from the breathing zone of neonatal foals can predict the occurrence of Rhodococcus equi pneumonia. rhodococcal pneumonia is a major issue in the equestrian breeding industry and early detection is essential to minimize the cost of treatment.

Methodology

• The researchers took air samples from the breathing zone of 53 neonatal foals (≤10 days old), and again when the foals were 1-2 months old during routine ultrasonographic screenings for R. equi pneumonia.

Results

• The study found that 23% of the foals were diagnosed with pneumonia through ultrasonographic screening. Virulent R. equi was detected in the air from the breathing zone of 19% of neonatal foals and 45% of foals at age 1-2 months.
• Despite this, no correlation was discovered between the presence of virulent R. equi in the breathing zone of foals and the subsequent ultrasonographic diagnosis of rhodococcal pneumonia.
• The median concentration of virulent R. equi in the breathing air of both the neonatal and older foals was comparable to that in background air samples.

Conclusion

• The conclusions drawn from this study indicate that the detection of virulent R. equi from the breathing air of the foals did not provide a reliable indicator for predicting rhodococcal pneumonia in foals up to 2 months old.
• The researchers concluded that selective culture of air samples from the breathing zone of young foals is not more effective than early ultrasonographic screening at diagnosing the disease.
• However, the culture of such air samples can still be a useful epidemiological tool at the herd level for older foals.