DISEASES OE THE SKIN. 469 



BLEEDING SKIN ERUPTIONS, OR DERMATORRHAGIA PARASITICA. 



In China, Hungary, Spain, and other countries horses frequently 

 suffer from the presence of a threadworm {Filaria hcemorrhagica 

 Eailliet, F. imdtipapUlosa Condamine and Drouilly) in the sub- 

 cutaneous connective tissue, causing effusions of blood under 

 the scurf skin and incrustations of dried blood on the surface. 

 The eruptions, which appear mainly on the sides of the trunk, but 

 may cover any part of the body, are rounded elevations about the 

 size of a small pea, containing blood which bursts through the scurf 

 skin and concretes like a reddish scab around the erect, rigid hairs. 

 These swellings appear in groups, which remain out for several days, 

 gradually diminishing in size ; new groups appear after an interval 

 of three or four weeks, the manifestation being confined to three or 

 four months of spring and disappearing in winter. A horse will 

 suffer for several years in succession and then permanently recover. 

 A fatal issue is not unknown. To find the worm the hair is shaved 

 from the part where the elevations are felt, and as soon as a bleeding 

 point is shown the superficial layer is laid open with the knife, when 

 the parasite will be seen drawing itself back into the parts beneath. 

 The worm is about 2 inches long and like a stout thread, thicker 

 toward the head than toward the tail, and with numerous little 

 conical elevations (papillae) around the head. The young worms 

 are numerous in the body of the adult female worm. The worm has 

 become common in given localities, and probably enters the system 

 with feed or water. 



Treatment is not satisfactory, but the affected surface should be 

 kept clean by sponging, and the pressure of harness on any affected 

 part must be avoided. Thus rest may become essential. The part 

 may be frequently washed with a strong solution of potassium sul- 

 phid. 



SUMMER SORES FROM FILARIA IRRITANS. 



The summer sores of horses (dermatitis granulosa, boils) have 

 been traced to the presence in the skin of another parasite, 3 milli- 

 meters in length and extremely attenuated {Filaria irritans Railliet). 

 The sores may be seen as small as a millet seed, but more frequently 

 the size of a pea, and may become an inch in diameter. They may 

 appear on any point, but are especially obnoxious where the har- 

 ness presses or on the lower parts of the limbs. They cause intense 

 and insupportable itching, and the victim rubs and bites the part 

 until extensive raw surfaces are produced. Aside from such friction 

 the sore is covered by a brownish-red, soft, pulpy material with 

 cracks or furrows filled with serous pus. In the midst of the softened 

 mass are small, firm, rounded granulations, fibrinous, and even 

 caseated, and when the soft, pultaceous material has been scraped 



