Lungworms (Dictyocaulus arnfieldi): prevalence in live equids in Kentucky.

Prevalence of natural infections of the lungworm, Dictyocaulus arnfieldi, was investigated in Kentucky in 5,437 live equids (horses, ponies, and asses) on 91 farms by examination of fecal samples over a 15-month-period from January 28, 1983 to April 19, 1984. For the 91 farms investigated, asses only were examined on 1 farm; for the other 90 farms, examinations were made of horses on all of them, of ponies on 4 farms, and of asses on 9 farms. Larvae of D arnfieldi were found in fecal samples of 112 (2%) of 5,379 horses on the 90 farms of which 38% had greater than or equal to 1 infected animal; none of 19 ponies examined was infected. For 39 asses (donkeys and mules) examined, 21 (54%) were infected; infected asses were present on 80% of the 10 farms on which they were examined. The equids, excluding asses, that were examined and the percentage (in parentheses) infected with D arnfieldi included 4,329 (2%) Thoroughbreds, 684 (2%) Standardbreds, 78 (0%) American Saddle Horses, and 307 (3%) miscellaneous (other breeds or mixed breeds of horses and ponies). Equids were separated into 3 categories relative to previous treatment with ivermectin: A (no treatment), B (treatment), and C (treatment unknown).(ABSTRACT TRUNCATED AT 250 WORDS)