dou·rine 
(d-rēn)
(d-rēn)n.
A contagious disease of horses, asses, and mules caused by the protozoan parasite Trypanosoma equiperdum, which is transmitted during copulation.
[French, from Arabic darina, mangy (said of a female camel), feminine of darin, dirty, from darina, to be dirty; see drn in the Appendix of Semitic roots.]