CHAPTER XXYIII; 



Revolution "Wrought by the Microscope — Sheep Both, or Grubs m 

 the Head — The Fluke Disease, or Liver Rot — Descriptions op 

 Different Varieties of Fluke — Vermicular Bronchitis — Turnsick, 

 Sturdy, or Gid. 



NO class of ailments with wh|ch sheep are affected occasion more 

 pain and torture to the animals themselves, or cause greater 

 annoyance and loss to shepherds, than those produced by par- 

 asites. These diseases are divided into two kinds, — those in which 

 the parasites infest the internal parts and organs of the sheep, and 

 those in which they infest the external ones. 



PARASITIC DISEASES OF THE INTERNAL PARTS. 



The diseases caused by the parasites infesting the internal parts 

 are liver rot, riieasles, bladder-worms, turnside (or giddiness), vermic- 

 ular bronchitis, etc. The most prominent of these parasites are the 

 different varieties of the fluke, the lung-strongle (or lung thread- 

 worm), hydatids (or bladder-worms) of various kinds, the tape- 

 worm, and the hair-worm ; while the parasitic diseases of the skin 

 are mainly caused by the scab insect, the sheep-louse, the gad-fly, 

 and the blue-bottle fly, the larvae of which are the maggots of de- 

 caying animal matter. 



The microscope has wrought a radical revolution in the theory 

 and treatment of parasitic diseases. That which was once taken for 

 the effect of certain diseased conditions of the system, is now recog- 

 nized as the cause ; and instead of animalculae being bred in dis- 

 eased matter, they themselves generally breed the disease. . But, 

 notwithstanding the invaluable contributions which science has 

 made to this branch of knowledge, there is no subject upon which 

 there is less correct knowledge diffused among American farmers. 

 And yet, as stated, the destructiyeeffects of parasitic diseases among 

 sheep as well as among other domestic animals of our country, 

 are appalling, and should command the closest attention and study 

 of every breeder and wqol-grower. These parasites are mostly 

 common to all domestic animals, although special varieties of them 

 are more numerous in some creatures than in others. 



(909) 



