Evidence of an Oxyspirura petrowi epizootic in northern bobwhites (Colinus virginianus), Texas, USA.

We captured 36 Northern Bobwhites (Colinus virginianus) in Mitchell County, Texas in June-September 2013, and examined them for the eyeworm Oxyspirura petrowi. We recovered 334 eyeworms from 28 of 29 adult bobwhites (97%); infections ranged from 1-40 worms and mean (± SD) abundance of 11.9 ± 13.0. Three of seven juveniles were infected, and those infected had one eyeworm each. Prevalence of eyeworms was similar among months. However, mean abundance of eyeworms peaked in July and August (3.3 ± 2.1, 13.5 ± 15.0, and 16.9 ± 15.5), and decreased in September (6.3 ± 3.0). We suggest that several previous studies may underreport prevalence and abundance because in those studies only the eye surface and nictitating membrane were examined, and not eye-associated tissue, ducts, glands, or sinuses.