68 RELATION OF INTESTINAL WORMS TO HYGIENE 



surface. The soft liquid nourishment is derived from the material within 

 the digestive canal of the host. The tape or flat-band worm is not con- 

 tinuous but is made up of segments or proglottides, each of which contains 

 vital organs, and in the posterior end of the worm each segment contains a 

 complete set of reproductive organs. As rapidly as the ova are fertilized 

 they are received into a uterus which is distended with eggs. The segments 

 drop off one by one and reach the exterior in the feces of the host. In this 

 way the upper surface of the soil over which the poultry range becomes 

 infested. Each egg contains an embryo, consisting of a round mass of 

 cells, bearing chitinous hooks. As soon as the egg has been discharged it is 

 necessary that it reach the intestinal canal of a second kind of animal 

 which is the intermediate host. This is necessary in order that the embryo 

 may enter the next phase of its life history. 



The six-hooked embryo known as an oncosphere or hexacanth embryo, 

 bores its way from the intestines into the body cavity of the intermediate 

 host. In the case of tapeworms in poultry, this is thought to be a true 

 worm, snail, crustacean or an insect. In this intermediate host it develops 

 into a larval form known as a cysticeroid. In turn this larva develops into 

 an adult worm when swallowed by a chicken and causes the formation of 

 the denuded areas along the intestinal tract. Grassi and Rovelli state that 

 the larva of Drepidotaenia infundibuliformis may be transmitted to birds 

 through the house fly as an intermediate host. According to Piana in 1882 

 the larva of Taenia tetragona was found in snails of the genus Helix. He 

 holds that this is a common means of the infestation of tapeworms among 

 domestic fowls. 



If intestinal worms are detected in the droppings this is indicative that 

 there is great probability that the land over which the birds range may be 

 infested with the worms in some stage of their life. If this be the case, and 

 our experience here at Maryland has shown it to be so, then the first 

 hygienic principle to be employed is a primary and fundamental one in the 

 science of hygiene, namely: prevention. 



Every part of the poultry house should be thoroughly disinfected with 

 a 5 to 10% solution of zenolium or some other good disinfectant. If these 

 birds appear badly infested every individual bird should receive a purgative 

 dose of Epsom salts followed by a few drops of turpentine. Finally, every 

 part of the poultry yards should be plowed, thus bringing the eggs or larva 

 of the infectious parasites to the surface and destroy them as far as possible 

 by the disinfecting action of the sun. Lime should be used freely and if 

 possible the land sweetened by vegetation. These few principles observed 

 will greatly correct the conditions which have existed during infestation of 

 the premises with intestinal worms. 



