AFRICAN HORSE-SICKNESS— PESTIS EQUORUM 369 



of the year. Fairly good results have been obtained by pre- 

 ventive inoculation to produce immunity. As in hog-cholera 

 a combined virus and serum vaccination is practised. 



Heartwater. — ^Definition. — ^Heartwater is a disease which is 

 not identical with horse-sickness. It is a contagio-iafectious 

 hydropericardium of cattle, sheep and goats of the Transvaal. 

 The disease is carried by ticks (Amblyomma hebreeum). 



24 



Digitized by Microsoft® 



