Relationships of Trichomonas gallinae to the palatal-esophageal junction of ring doves (Streptopelia risoria) as revealed by scanning electron microscopy.

Ring doves (Streptopelia risoria) were experimentally infected with pathogenic (virulent) Trichomonas gallinae so that trichomonad activities in the upper alimentary tract, prior to canker formation, could be examined with scanning electron microscopy. Between 6 and 15 hr postinoculation low numbers of ameboid T. gallinae were attached to apical microfolds and cell borders of the palatal-esophageal junction squamous epithelium. Initial parasite activities at tightly attached cell borders and apical microfolds suggest that some parasite-secreted factor or factors initiated squamous cell damage, separation, and removal. As squamous cell borders separated, trichomonads invaded areas beneath them and ultimately aided in their complete removal. Accelerated parasite-mediated desquamation, the invasion of increased mucosal surface area by trichomonads, and the eruption and expansion of cankers were the primary changes to the palatal-esophageal junction and other upper alimentary tract tissues that occurred between 19 and 240 hr postinoculation.

Ectoparasites of black-tailed prairie dogs (Cynomys ludovicianus) from South Dakota.

During the summers of 1982 and 1983, black-tailed prairie dogs (Cynomys ludovicianus) were examined for parasites. Those collected and their respective prevalence included Linognathoides cynomyis (46.3%), Opisocrostis hirsutus (53.7%), Opisocrostis tuberculatus cynomuris (2.4%), Androlaelaps fahrenholzi (12.2%), Ixodes sculptus (2.4%) and Dermacentor andersoni (4.9%). The collection data indicated that L. cynomyis, O. hirsutus and A. fahrenholzi were at low population densities during this period.