Intestinal Parasites of the Dog. 297 



Habitat. Pathogenesis. These worms inhabit the large intes- 

 tine, mainly the caecum, and are found with head and neck deeply 

 buried in the mucosa for the purpose of sucking blood or plasma. 

 When present in small numbers only, they are comparatively 

 harmless, but in large herds, on damp yards, or drinking infested 

 water they may be found in large numbers and cause diarrhoea, 

 indigestions, colics and unthrift. They are to be treated like 

 other intestinal nematoids. 



Trichina Spiralis. (Owen). All forms of the trichina are 

 found in the bowels of swine : — the embryo introduced in water 

 or just produced by the mature female worm : — the larvae or 

 encysted worm introduced with trichinous meat, or free after the 

 meat and cyst have been digested : — and the sexually mature in- 

 testinal trichina. The two former are, however, only transitory 

 guests as they speedily bore their way through the walls of the 

 bowels to encyst themselves in the voluntary muscles, while the 

 mature parasite .spends the full measure of its existence in the 

 bowels and fulfills its destiny in propagating its kind. (See 

 under Muscular Parasites^. 



Anguillula Suis. Rhabdonema Suis (I^utz). yke the 

 anguillula of man, this is .smaller than that of the ruminant. 

 Lutz claims that it can only be hatched outside the body unlike 

 that of man which can be hatched in the intestine. He further 

 claims that in Brazil where the anguillula of man abounds, that of 

 the pig is rare, though hogs run at large and have every oppor- 

 tunity of devouring human faeces and the water that drains from 

 them. They are not known to prove injurious to pigs, probably 

 because of their infrequency. 



INTESTINAL PARASITES OF THE DOG. 



Lamblia Intestinalis : Coccidium Perforans in intestinal epithelium, 

 causes local inflammation, indigestion, anorexia, colic, diarrhoea, ner- 

 vous symptoms, emaciation. Coccidium Bigeminum in pairs in villi of 

 small intestine. Cestodes : Table of tape-worms of dog. T. Serrata, from 

 preying on rabbits and hares ; 20 to 60 inches ; armed protractile proboscis, 

 34 to 38 hooks ; larva cysticercus pisiformis in peritoneum, etc., of rabbit, 

 ■which eats grass or drinks water having the eggs. T. Serialis : Small in- 

 testine, from preying on rabbits ; 15 to 25 inches long ; protractile proboscis 



