Intestinal Parasites of the Dog. 313 



both countries, and the aggregations of ruminants and dogs, 

 together with the simple nomadic life of the shepherds, strongly 

 conduce to the preservation and spread of the parasite. 



Treatment. No drug is known which given internally will kill 

 the echinococcus cyst. Klectricity though warmly advocated by 

 some has proved unsatisfactory. Yet spontaneous recovery is 

 not unknown, through the rupture and evacuation of the cysts or 

 through the death of the echinococcus and degeneration of its 

 contents. When ruptured it may be recognized by the density of 

 the liquid (1007 to 1009), by the excess of sodium chloride, the 

 absence of albumen and above all by the presence of heads 

 (scolices) or booklets. An exudate of blood or lymph beneath 

 the outer layer of the cyst may be the occasion of its death. The 

 exudate degenerates into a sebaceous like debris, which com- 

 pressing the inner membrane causes it to pucker up and expel its 

 liquid contents. As the exudate increases the cavity grows 

 gradually smaller and is finally obliterated or retains only the 

 booklets of the dead scolices. The debris may resemble putty or 

 chalk, though in man it may suggest softened tubercle. 



The evacuation of the cyst by trochar and cannula, followed by 

 injection with tincture of iodine to be left in the cyst for five min- 

 utes and then drawn off has repeatedly succeeded. The contents 

 of the cyst are first thoroughly drawn out by the aid of a syringe, 

 then the iodine is injected, left for five minutes and again fully 

 drawn off. If the trochar has to penetrate any serous cavity 

 great care is taken to prevent any scolices from escaping into 

 this. Also, whenever a hydatid is laid open by spontaneous rup- 

 ture, by the knife, or by the trochar, the walls of the sac should 

 be extracted if possible, as this will absolutely prevent its reap- 

 pearance in situ. 



Prevention. While the wolf is a possible source of the echino- 

 coccus ova, it is to the dog that we must look as the almost ex- 

 clusive source of the parasite in well settled and cultivated dis- 

 tricts. In the dog the disease can be recognized and the propa- 

 gation of the parasite through the mature worms and their eggs 

 can in him be arrested, so that by attention to the dog this deadly 

 tape-worm can be exterminated. Effective measures should in- 

 clude the following : i . The destruction of all superfluous dogs 

 and especially of homeless and neglected ones. 2. The strict 



