T&NIASlft 199 



directly related to that of the cystic or bladder worms 

 infesting ruminants, rabbits, and other intermediate hosts. 

 The number of individuals by which each of these teenia3 

 may be represented in the same dog is also variable. The 

 Dipylidium caninum varies up to 360, the T. pisiformis as 

 high as 64, the T. hydatigena and the M. rnulticeps usually 

 less than 10, but the Echinococcus granulosus from one to 

 several thousand. This variation is due in part to the fact 

 that some cyst forms give rise to but one adult parasite 

 (monocephalic), while others produce many (polycephalic). 

 The common location of the tsenia is in the small intestine; 

 only occasionally does it migrate to other parts of the diges- 

 tive canal. The head is attached to the mucosa by suckers or 

 hooks, and as the body may be folded on itself many times 

 long parasites may only occupy a short distance of the bowel. 

 Large numbers are often massed together almost completely 

 occluding the lumen of the bowel. The mucosa is hyperemic, 

 thickened and covered with mucus. Some of the glands are 

 hypertrophied. Rare cases of perforation of the walls by 

 tsenise have been reported, but as a rule the pathological 

 changes are those of a chronic enteritis. 



Symptoms. Notwithstanding their extreme frequency, the 

 tsenise often have no apparent influence on the health of the 

 dog. Sometimes, however, by their accumulation and intes-j 

 tinal obstruction, they cause abdominal pain or a chronic 

 enteritis. The appetite is often irregular, but while the 

 patient may eat well its condition remains bad. Growth is 

 checked, emaciation often develops, and the hair coat loses 

 its normal luster. Young dogs are uneasy, change their 

 position frequently and show a desire to bite the skin over 

 the abdomen. They may have epileptiform attacks.which 

 are periodical, with normal intervals between. When fre- 

 quent, these attacks may be followed by a gradual sinking 

 and death. 



The Tsenia tseniseformis of cats is frequently found in large 

 numbers in the small intestines and occasions serious dis- 

 ease. The appetite gradually declines. A slight diarrhea is an 

 early symptom followed by constipation; salivation is abun- 

 dant; great prostration; nervous phenomena as loss of sight 



