Potomac horse fever

noun
Po·​to·​mac horse fever | \ pə-ˈtō-mək- How to pronounce Potomac horse fever (audio) , -mik- How to pronounce Potomac horse fever (audio) \

Medical Definition of Potomac horse fever

: an often fatal disease of horses that is marked by fever, loss of appetite, diarrhea, and laminitis, that is caused by a bacterium of the genus Ehrlichia (E. risticii), and that was discovered in the region of the Potomac River in Maryland but is much more widespread

called also Potomac fever