Lack of residual lung damage in horses in which Rhodococcus equi-induced pneumonia had been diagnosed.

The research primarily focuses on analyzing whether horses previously stricken by Rhodococcus equi-induced pneumonia have any remaining lung damage. After studying five horses under two years old that have had the illness, the researchers concluded that there was no significant long-term lung damage in horses that have recovered from this type of pneumonia.

Research Methodology

• The researchers selected five horses less than 24 months old that had been diagnosed with Rhodococcus equi-induced pneumonia based on positive results of transtracheal aspiration and thoracic radiography when they were foals.
• These horses were re-evaluated using various methods such as endoscopy, radiography, hematologic and bronchoalveolar lavage analyses, and pulmonary function testing.
• The results from the horses that had previously suffered from pneumonia (R+) were then compared with those of five age-matched healthy horses (R-) that did not have a history of foalhood pneumonia.

Findings and Observations

• Overall, no significant differences in variables between the two groups of horses were found.
• In both groups, most of the horses had radiographic evidence of an accentuated bronchointerstitial pattern. This means that the lung tissues of the horses in both groups appear similarly under radiographic imaging.
• The analysis of bronchoalveolar lavage specimens were normal and mononuclear cells were predominant, indicating a healthy condition in the lungs.
• Although there was variability in the results of the pulmonary function tests within and between the two groups of horses, normalized dynamic lung compliance was slightly lower in the previously infected horses. However, this difference was not statistically significant.

Conclusion

• The researchers concluded that horses previously infected with and successfully treated for Rhodococcus equi-induced pneumonia do not show any detectable evidence of residual lung damage.
• This indicates that the lung function in horses can completely recover from this type of pneumonia, suggesting that once successfully treated, these horses can expect to have a normal respiratory health similar to those never infected.