'“Modern researchers, (Victor ) Mair notes, have come up with two different ideas (the ancient Chinese references to the “Blood-sweating” horses of Ferghana ). The first suggests that small subcutaneous blood vessels burst as the horses sustained a long hard gallop. The second theorizes that a parasitic nematode, ''Parafilaria multipapillosa'', triggered the phenomenon. P. multipapillosa is widely distributed across the Russian steppes and makes its living by burrowing into the subcutaneous tissues of horses. The resulting skin nodules bleed often, sometimes copiously, giving rise to a something veterinarians call “summer bleeding.”〔(The Emperor and the Parasite ). The Last Word On Nothing (2011-03-03). Retrieved on 2011-03-17.〕