30 



CIRCULAR 338, U. S. DEPT. OF AGRICULTURE 



Figure 29.— Egg of 

 the serrate dog tape- 

 worm, Taenia pirifor- 

 mis. Enlarged. 

 From Railliet, 1893. 



bothrium latum, and the cat tapeworm, Taemataeniaejorrnis (synonym, 

 T. crassicottis), the latter species being the most important. Taenia 

 taeniaeformis is from 6 inches to 2 feet (15 to 60 centimeters) long, the 

 head is armed with a double circlet of hooks, and the suckers, four in 

 number, are prominent, pointing forward and outward; there is no 

 neck, segmentation beginning immediately back of the head, and the 

 first segments being as broad as the head or 

 broader. The bladder-worm -stage of this tape- 

 worm occurs in the livers of rats, mice, muskrats, 

 and otper rodents. Cats become infested by eat- 

 ing the infested livers of these animals. 



Symptoms. — In general, tapeworms in the dog 

 may cause disturbances in appetite and digestion, 

 a disposition to vomit, general restlessness, and 

 sometimes cramps. In heavy infestations they may 

 cause an inflammation of the digestive tract and 

 occasionally cause occlusion, or stoppage, of the 

 intestine by filling and blocking the intestinal 

 lumen. In addition, tapeworms in heavy or even light infestation 

 may cause more or less well-marked nervous disturbances, in some 

 cases simulating rabies. The passage of a segment or a string of 

 segments through the anus often causes itching or irritation, mani- 

 fested by the dog's sitting down and dragging itself forward on 

 its haunches. This symp- , 



torn is sometimes said to -'.V^/' ".•"-- 



be due to pinworms in _-:.V^U;..." l r:>:'M 'V;* ''"'■■ 



the dog, but dogs do not 

 have pinworms. The com- 

 mon double-pored tapeworm 

 is especially likely to cause 

 this symptom, and seg- 

 ments of this worm are 

 sometimes referred to as 

 pinworms or rectal worms. 



Cats infested with Taenia 

 taeniaeformis may show loss 

 of appetite, transient diar- 

 rhea followed by constipa- 

 tion, salivation and, in 

 some cases, persistent vom- 

 iting. In kittens the ab- 

 domen may be distended, 

 the animals exhibiting evi- 

 dences of acute abdominal 

 pain. Nervous symptoms, such as epileptiform convulsions, have 

 been reported as symptoms of tapeworm infestation of cats. 



Treatment. — One of the most effective treatments for the removal 

 of tapeworms from dogs consists in the administration of arecoline 

 hydrobromide in doses of one-eighth grain to small dogs, one-fourth 

 grain to dogs of medium size, and one-half grain to large dogs. The 

 treatment is given in the morning after food has been withheld over- 

 night, and no food is given for 3 hours after dosing. No purgative is 

 given with this drug, as the drug usually is itself a very fast and 

 effective purgative. The efficacy of arecoline hydrobromide is said to 



Figure 30.— Sheep muscle showing two bladderwonns, 

 Cysiicercus ovis. Actual size. From Hall, 1921, after 

 Ransom, 1913. 



