Is Chorioptes texanus to Displace Chorioptes bovis? Notes on the Mites Causing Bovine Chorioptic Mange in Central Europe

Chorioptic mange is the most common type of bovine mange in central Europe, affecting mainly housed dairy cattle. Until 1976, when Chorioptes texanus were described for the first time from mangy cattle in Brazil, bovine chorioptic mange was thought to be caused only by C. bovis mites. In Europe, C. texanus parasitism in cattle was for the first time reported in Germany in 1998. Following the repeated diagnosis of C. texanus mites in skin scrapings from local cattle in recent years, scrapings from cattle that were clinically suspicious for chorioptic mange were requested and provided during the years from 2019 to 2022 from Austria, France, Germany, and Switzerland (from 6, 17, 28, and 7 farms, respectively) and from dairy cows of 1 farm in Canada. Mites were isolated from the scrapings, cleared, and microscopically identified based on their morphology. Examination of scrapings revealed the presence of C. texanus in the cattle from 2 farms in Austria, 13 farms in France, 7 farms in Germany, 1 farm in Switzerland, and in the specimens from Canada. Chorioptes bovis mites were recovered only in scrapings from 5 farms in Germany and Psoroptes ovis mites in scrapings of cattle from 2 farms in France. The scrapings did not reveal co-infestations of C. bovis and C. texanus or of Chorioptes species and P. ovis. The records of C. texanus from Austria, France, Switzerland, and Canada constitute the first descriptions of this mite species in these countries. Although this investigation was based on an opportunistic collection of the material and was of small extent, the results suggest a widespread occurrence of C. texanus in central Europe and may emphasize the need for studies to closely investigate the nature of the causative agents of chorioptic mange in cattle and other hosts.