SHEEP TICKS. 



315 



There are also convulsive movements of the body and 

 legs, and more or less increase of fluid in the spinal cord. 

 Veterinarians are not agreed as the cause of the dis- 

 ease, but as good food and pure water are preventives of 

 it, bad food and impure water must be predisposing causes 

 of it. 



Fig. 149. Sheep Tick. 



Lonping-ill is only seen on land infested with ticks. 

 Ticks are the cause of the disease. It is possible, how- 

 ever, to have land infested with ticks and yet have sheep 

 free of louping-ill, as all ticks do not seem to contain 

 disease germs. 



Improve moors and pastures where it exists. The cure 

 is uncertain, but many sheep recover. 



Fig. 150, Louping-ill or Hydro-Rachitis. 



