268 Veterinary Medicine. 



Treatment. As it is taken in as cercaria this may be prevented 

 by giving due attention to the water and food (see distomatosis). 

 Otherwise it may be treated by salt and other vermifuges. 



ROUND WORMS, (NKMATOIDS) OF SOLIPEDS. 



Ascaris Megalocephala (jmegalocephalos large head). While 

 ascarides are distinguished by their relatively large size, this 

 species is larger than others. The male is 5 to 9 inches, and the 

 female from 6 to 15 inches in length. It is further distinguished 

 by its large head expanding at the end of a neck, and furnished 

 with three papillary lips bearing teeth on their free margin. The 

 male has its tail furnished with two lateral membraneous alse, and 

 a great number of papillae, which are in two rows behind the anus 

 and in several rows more anteriorly, also two cylindroid, curved 

 spicula. The female has its tail conoid and obtuse, anus nearly 

 terminal and vulva toward the anterior fourth of the body. Ova 

 almost globular, and have great vitality, the contained embryos 

 remaining alive for two years in water, dung, moist earth, or on 

 glass slides. Hence they can remain in wells, ponds, and the 

 dust of stables and yards to enter the system with the food and 

 water. 



Habitat. The small intestines of solipeds : very common and 

 often in great abundance. 



Pathogenesis. They often produce no visible symptoms in 

 mature solipeds, but in the young, and if in great numbers in the 

 old as well, they prove very injurious. At the Brussels Veteri- 

 nary School more than 1800 were found in one horse, and the 

 present writer has collected a gallon which were passed by one 

 subject under the use of vermifuges, and on another occasion has 

 taken as many from the small {ni&siin&s post mortem. They have 

 been found to pass into the stomach (Neumann), the bileduct 

 (Roll) and the pancreatic duct (Generali). 



Colics, indigestions, slight muco-enteritis, and watery diarrhoea 

 may be noted as among the local lesions and disorders caused by 

 these worms. Gavard, Wirz and Zurn have cited cases, in which 

 the worms seemed to have perforated the intestinal mucosa and 

 escaped into the peritoneum. Hepatic and pancreatic disorder 



