| Parafilaria multipapillosa | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Nematoda |
| Class: | Secernentea |
| Order: | Spirurida |
| Family: | Filariidae |
| Genus: | Parafilaria |
| Species: | P. multipapillosa |
| Binomial name | |
| Parafilaria multipapillosa |
|
Parafilaria multipapillosa (syn. Filaria haemorrhagica) is a parasitic nematode of the genus Parafilaria,[1] which affects horses causing hemorrhagic subcutaneous nodules in the head and upper forelimbs, in North Africa, Southern and Eastern Europe, Asia and South America, leading to bleeding from the skin. It is commonly referred to as "Summer bleeding".
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P. multipapillosa is related to Parafilaria antipini which are found in deer, and Parafilaria bovicola which causes hemorrhagic nodules in the skin of cattle and buffalo.[1]
The nematode is thought to be passed by blood-sucking Haematobia spp [biting flies] in spring and summer. It causes skin nodules, particularly on the head and upper forequarters, which often bleed profusely (“summer bleeding") but then usually resolve, though occasionally suppurating. The nodules and bleeding, though annoying and unsightly are generally are of little consequence. The clinical signs are pathognomonic. No effective treatment is available.[2]
'“Modern researchers, [Professor Victor] Mair notes, have come up with two different ideas [for 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.”[3]
Over 2,100 years ago two Chinese armies traveled 10,000 km to find "Heavenly Horses" or Ferghana horses, apparently infected with a tiny worm causing them to "sweat blood" from skin sores:
"Sometime earlier the emperor [ Wudi ] had divined by the Book of Changes and been told that "divine horses are due to appear" from the northwest". When the Wusun came with their horses, which were of an excellent breed, he named them "heavenly horses". Later, however, he obtained the blood-sweating horses from Dayuan [= Ferghana], which were even hardier. He therefore changed the name of the Wusun horses, calling them "horses from the western extremity", and used the name "heavenly horses" for the horses of Dayuan."[4]
P. multipapillosa is thought to have been the cause of the "blood-sweating" of these famous and much desired horses from Ferghana, which Emperor Wu of Han China (Wudi) renamed "Heavenly Horses" (c. 113 BCE). He sent an army of 40,000 men in 104 BCE the 5,000 km to Ferghana, but they were defeated. Another army of 60,000 men was sent in 103 BCE and they managed to negotiate the acquisition of 3,000 horses (though only a few dozen were top class and only 1,000 made it all the way back to China in 101 BCE). However, they did also get an agreement that Ferghana would send two Heavenly horses each year to the Emperor, and lucerne seed was brought back to China providing superior pasture for breeding raising fine horses in China, to provide cavalry which could cope with the Xiongnu who threatened China.[5][6]