996 Parasitic Thread Worms in tlie Skin. 



by the plough (Bissaiige). The symptoms are similar to those 

 of bee stings (B. Kovacs saw sjTiiptoms similar to those of 

 hydrophobia in a dog [Vet., 1895, 361]). 



25. Parasitic Thread Worms in the Skin. 



The thread worms which are parasitic in the skin and sub- 

 cutaneous connective tissue of mammalia belong to the family 

 of Filaria. Of this class the following varieties are known : 



1. Filaria hemorrhagica. A fine, thread-like worm which 

 shows transverse striae on its white body, while its head end is 

 covered with a round papilla-like prominence ; the male 28 mm., 

 the female 40 to 70 mm. long. The course of evolution is un- 

 known. 



In its mature state the parasite lodges in the subcutaneous 

 and intermuscular connective tissue of horses of oriental de- 

 scent (Hungarian, Russian, Tartaric) and causes frequent 

 cutaneous hemorrhages in spring and summer, the socalled 

 summer hemorrhage (Drouilly, Trasbot, Megnin, v. Ratz and 

 others). 



The exuding blood lifts the skin or the epidermis in the 

 form of a lentil or hazelnut-sized nodule, which bursts in 1 to 2 

 hours, whereupon blood exudes for a time from the fine open- 

 ing thus formed ; after a while, however, the bleeding ceases and 

 the slight wound heals. The nodules form as a rule in great 

 number and close together, but only in the warm time of the 

 year. The disease may recur annually in the same horse for 

 3 or 4 years, but afterwards disappears completely. 



Unless severe anemia is caused through the hemorrhage 

 (Bruncwic, Liautard), the health of the animals is not affected. 

 The complaint is chiefly annoying, because the exuding blood 

 soils the skin and harness. The treatment consequently con- 

 sists only in frequent washing and cleaning of the skin, and 

 besides it appears advisable to protect the bleeding region from 

 chafing by the harness wherever possible. 



Literature. Condamine & Drouilly, Eec, 1878, 1144. — Eailliet, Zool. med., 

 1895, 507.— Eailliet & Moussn, C. E., 1892, 545.— v. Eatz, Vet., 1898, .393. 



2. Filaria irritans. The silver white cylindrical larva, 2 

 to 3 mm. long, of an hitherto unknown thread worm (Rivolta, 

 Laulanie). According to Roger it may be the larva of OxAT^iris 

 equi (see page 487). It resides in the subcutaneous connective 

 tissue of horses and causes a skin disease described by the name 

 of dermatitis granulosa s. pruriginosa s. verminosa C Summer 

 sores" [French]). These are noticed exclusively in horses 

 in the summer, and manifest themselves by the formation of 

 little nodules in the skin, where it comes in contact with the 

 harness, and on the legs, also not infrequently on other 

 parts of the body, and even in the conjunctiva of the eyes 



