336 VETERINARY HYGIENE 



mortality sometimes occurs among young chicks and young 

 turkeys. 



The male and female parasites, of which the former is the 

 smaller, are in more or less constant union, and when the pregnant 

 female is coughed up on to the poultry runs the eggs are either 

 scattered about the ground or the worms themselves are eaten 

 by the chicks so that the eggs and embryos pass on the infection 

 without the necessity of an intermediate host. 



It has been pointed out that earthworms eat the eggs and are 

 themselves in turn eaten by chicks, the worms acting as accidental 

 hosts and not as necessary ones.* Illness and death of the infested 

 birds is due to bronchitis, weakness and anaemia due to the constant 

 irritation and loss of blood from the parasites sucking blood from 

 the mucous membranes, and also from suffocation. 



PREVENTIVE MEASURES. Overcrowding should be avoided. 

 Sick birds must be isolated, chicks should be kept on clean ground 

 and the ground on which they are reared should be changed from 

 year to year. Infected runs should be dressed with freshly-slaked 

 lime, which should be well raked in. Hen coops, and feeding and 

 drinking utensils must be thoroughly cleansed and disinfected. 



Infected chicks will require suitable treatment, and those that 

 die should be burnt. 



BLADDER WORMS. 



These are the larval forms of the adult tape-worms or cestodes. 

 The three groups of importance to the veterinary hygienist are : 

 (1) cysticercus; (2) ccenurus; (3) echinococcus. The cysts or 

 " bladders " are found in various parts of the bodies of their hosts 

 according to the site for which each species has a predilection. 

 Specific injury done to the host depends upon the peculiar location 

 of the cysts, as will be shown later. Apart from immediate 

 injurious effects, which the presence of the cysts causes, they 

 depreciate or even render valueless the flesh of infected animals; 

 furthermore, as they are the precursors of the adult tapeworms, 

 their destruction is as important as that of the worms themselves. 



CYSTICERCOSIS. Each cyst contains but one head and can give 

 rise to but one adult worm. 



C. celluloses. Of chief significance in the pig, though it has also 

 been found in man, the dog and the cat. Fillers gives its most 

 common sites in the pig as the shoulder, neck, tongue, intercostal 

 and psoas muscles. In bad cases any muscles may be involved, 

 though it is but rarely found in the internal organs. 



* Leaflet No. 58, 1918, Board of Agriculture and Fisheries. 



