PREVENTION OF VBEMIOEOUS DISEASES. 485 



the affected ones, and avoid foul pastures. In gapes, however, 

 allowing a drop of camphorated or eucalyptus oil to run down the 

 trachea is always satisfactory, and perhaps is the best way to treat 

 birds when only a few are attacked ; but when large numbers have 

 gapes the use of the funiigating-box is axivisable. Blowing into the 

 box, with bellows, finely ground camphor, chalk, and paraffin causes 

 the worms to relax their hold and the birds to cough, and so the 

 nematodes are expectorated. 



Flukes or trematodes are impossible to destroy, as far as our pres- 

 ent knowledge goes, when once fairly housed in the bile-ducts and 

 liver. Land along the edges of rivers and streams may be said to 

 be generally liable to be infested with trematode germs, which, as 

 pointed out previously, live in the water-snails {Liinnceus trun- 

 catuliis) during part of their early life. Certain meadows in which 

 these molluscs abound are sure to affect the flock ; such land should 

 thus be fed to beasts which, although sometimes subject to trema- 

 todes, are not seriously affected. Attention should be paid to the 

 moUuscau hosts, hordes of which may be destroyed, when cleaning 

 out the ditches and dykes, by casting lime over the mud brought 

 out, when not only the primary host but the embryo flukes are 

 killed. In all parasitic vermiceous diseases the sti-ength of the host 

 must be well maintained by good and rich feeding, so that the 

 invaded animal can withstand the extra drain on its system. This 

 and proper sanitary measures, the application of a few well-known 

 vermifuges, and the destruction of diseased parts instead of giving 

 them to dogs and other animals, are the main points in preventing 

 the too persistent losses from vermiceous diseases. 



In the case of infected food, which seldom now jiasses out of 

 the markets, thorough cooking destroys the cysts and germs of 

 various diseases, the chances of infection being very slight. Water 

 plays a jirominent part in the distribution of these complaints, and 

 where possible the purest spring-water only should be employed, 

 for stock as well as for man, especially during and after an 

 outbreak. 



