Precipitating antibodies against Micropolyspora faeni in equines in north-western India.

Prevalence of serum precipitins against Micropolyspora faeni, Thermoactinomyces vulgaris and Aspergillus fumigatus, employing the counterimmunoelectrophoresis (COIE) and Ouchterlony's double diffusion (DD) techniques, is reported in 162 of the equines stationed at two military installations in north-western India. M. faeni specific precipitins were demonstrable in 58 of 112 mules from site I in the mountainous region whereas the results were negative for all of the 50 horses examined from site II located in the plains. Of the 58 M. faeni positive mules, 45 (78%) had signs and symptoms suggestive of chronic obstructive pulmonary disease (COPD) while the remaining 13 (22%) were apparently free from any respiratory disorder. The more frequent occurrence of M. faeni precipitins in the symptomatic than in the asymptomatic group of mules was found to be statistically significant (P less than 0.01). Precipitins against A. fumigatus were concomitantly demonstrated in 5 of the mules afflicted with COPD and found to be positive for M. faeni.