226 The Management and Diseases of the Dog. 



imongst animals) the part these tapeworms are destined 

 :o play in the economy of life is not merely remarkable, but 

 iltogether unique." 



The first he notices is the cucumerine tapeworm {Tcenia 

 nccumerind) : " It is a delicate and almost transparent tape- 

 worm, measuring from ten to twenty inches in length." 



This parasite is very common in English dogs, and, 

 iccordingto Krabbe, infests 48 per cent, of the dogs in 

 Denmark, and 57 per cent, of the dogs in Iceland. The 

 inimals infect themselves in a singular manner. The 

 oints of the , worm, having escaped per anum, readily 

 :rawl, as semi-independent creatures on the coat of the 

 iog, chiefly on the back and side. The eggs thus dis- 

 :ributed are readily swallowed by the louse of the dog 

 [Trichodectes latus). 



In the body of the louse the six-hooked embryo, hitherto 

 :ontained in the egg of the tapeworm, escapes the shell 

 ind becomes transformed into a minute cysticercus or 

 ouse-measle. When the dog is irritated by the lice, it 

 ittacks, bites, and frequently swallows the offending 

 external parasite. In this way the louse-measle is trans- 

 "erred to the dog's intestinal canal, where, in course of time, 

 t develops into the sexually mature cucumerine tape- 

 A^orm. 



Thus the mange-mite, or scab insect (as it is rather 

 ncorrectly termed), serves as the intermediary bearer of 

 arval tapeworm, and forms an essential factor in the pro- 

 iuction of this particular species of cestode parasite. 



loes, according to the experiments of Luschka, Leuckart, and others, 

 n the organs of the domestic quadrupeds. 



" It is oi the greatest importance that careful and extended inquiries 

 ;hould be made as to the prevalence of these cysticerci in animals. It 

 s evident from the observations of Kiichenmeister and others that 

 nany individuals of these species, forming extensive cystic tumours, 

 ire to be found in pigs, and not unfrequently there has been a confu- 

 lion between cysticerci and echinococchi. Thus, in Ireland, the 

 :ndemic cystic disease appears to be due to both these hydatids." 



