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PARASITES AND PARASITIC DISEASES OF DOGS 27 



these symptoms appear, it is advisable to suspend treatment until the 

 temperature and pulse rate return to normal. 



Experiments indicate that some or all the adult worms are killed by 

 the drug. Treated animals usually show improvement in physical 

 condition, in heart action, and in working capacity. 



The drug may be used intravenously also, and the period of treat- 

 ment can be shortened by the use of this method. For a 40-pound 

 dog, the initial dose is 1.0 cubic centimeter; a dose of 2.0 cubic centi- 

 meters is given on the third day; on the fifth, seventh, and eighth 

 days, a dose of 2.5 cubic centimeters; and on the ninth, tenth, and 

 twelfth days, a dose of 5 cubic centimeters is administered. 



No standard dose rate for this drug can be prescribed, and emphasis 

 is placed on the fact that the dose must be judged on the basis of 

 degree of infestation and the physical condition, as well as the weight, 

 of the animal. In view of this fact, treatment should be administered 

 only by a veterinarian. Until experience is gained through the use of 

 the drug, a low dose rate should be used for the first 2 or 3 injections 

 in order to establish tolerance of the animal for the drug. In case of 

 severe reactions following the use of the drug, the administration of a 

 suitable dose of a 10-percent solution of calcium gluconate has been 

 found of value. 



Prevention consists in keeping dogs from being bitten by mos- 

 quitoes. Dogs should be kept away from places frequented by 

 mosquitoes, especially after sundown and in the early morning. 

 Keeping dogs in enclosures screened to keep out mosquitoes is sound 

 practice, and in the Fiji Islands mosquito-proof kennels with self- 

 closing doors have been used. 



TAPEWORM INFESTATION 



Cause. — Tapeworms are elongated, flat worms made up of few to 

 numerous segments and with a head which is usually provided with 

 4 suckers and 2 or more hook circlets. The head is located at the 

 small end of the worm. Dogs are infested with a number of kinds of 

 tapeworms, ranging in size from the small hydatid tapeworm, Echino- 

 coccus granulosus (synonym, Taenia echinococcus) , which is less than 

 two fifths of an inch (1 centimeter) long, to the marginate tapeworm, 

 T. hydatigena (synonym, T. marginata), which is from 2.5 to over 16 

 feet (75 centimeters to 5 meters) long, or to the broad fish tapeworm, 

 Diphyllobothrium latum (synonym, Dibothriocephalus latus), which 

 may attain a length of almost 30 feet (9 meters). All the dog tape- 

 worms live in the small intestine of the dog. All of them produce 

 eggs which pass out in the feces and which on being swallowed by a 

 suitable host animal will develop to a larval tapeworm, taking the 

 form of a bladderworm of some sort. The host of this bladderworm 

 will be in some cases a domesticated animal, such as the sheep, cow, 

 or pig; in some cases a wild animal, such as the hare or rabbit; in some 

 cases a fish; and in other cases an insect, such as the dog louse or flea. 

 In any case the bladderworm will not occur in the lumen of the 

 digestive tract, but will occur in the tissues, such as the lungs, liver, 

 muscles, mesenteries, brain, or intermuscular or subcutaneous con- 

 nective tissue, or in the body cavity. In the larger animals, such as 

 sheep, cattle, and swine, the bladderworms may be very large, as in 

 the case of the hydatid, which may attain the size of a child's head 

 and which is often the size of an orange; in insects, such as the flea or 

 louse, the bladderworm is very tiny, as it must be in a host of this size. 



