Dm. Ainsworth et al., LACK OF RESIDUAL LUNG DAMAGE IN HORSES IN WHICH RHODOCOCCUS EQUI-INDUCED PNEUMONIA HAD BEEN DIAGNOSED, American journal of veterinary research, 54(12), 1993, pp. 2115-2120
The effect of prior Rhodococcus equi-induced pneumonia on pulmonary he
alth was investigated in 5 horses (<24 months old) using endoscopy, ra
diography, hematologic and bronchoalveolar lavage analyses, and pulmon
ary function testing. Rhodococcus equi-induced pnuemonia had been diag
nosed in principal horses when they were foals. Diagnosis was based on
positive results of transtracheal aspiration and thoracic radiography
at the time of initial clinical examination. Results of reevalution o
f the respiratory system of these horses (R+) were compared with those
of 5 age-matched healthy horses (R-) that lacked clinical or historic
al evidence of foalhood pneumonia. Significant differences in variable
s between the 2 groups of horses were not evident. In both groups, mos
t horses had radiographic evidence of an accentuated bronchointerstiti
al pattern, although results of analysis of bronchoalveolar lavage spe
cimens were normal and mononuclear cells predominated. Variability in
results of the pulmonary function tests was observed within and betwee
n the 2 groups of horses. Only normalized dynamic lung compliance was
slightly lower in the previously infected horses, but this difference
was not significant. We concluded that horses previously infected with
and successfully treated for R equi-induced pneumonia do not have det
ectable evidence of residual lung damage.