summer rains, followed by heat and unusual heavy dews. For a 

 long time the dews and mists were looked upon as having a direct 

 bearing on the disease and horses were kept on high plateaus dur- 

 ing those months. After the first frosts have fallen the danger is 

 past.-" 



Towards the middle of the last century it was pointed out by 

 experts that the disease was closely related to Anthrax; but Dr. 

 Edington has the honor of pointijig out that it is a disease sui 

 generis and that it can be transmitted to horses by subcutaneous 

 inoculation with the blood of an animal that died of the disease. 



Towards the close of the last century Ijt. Col, Walkins-Pitchford 

 definitely proved the theory that the disease was caused by the bites 

 of nocturnal insects; and also succeeded by tracing the insect to 

 be the Anopholes Mosquito. 



In 1903 the Chief of the Veterinary Department, Dr. now Sir. 

 Arnold Theiler first succeeded in getting a preventive inoculation 

 whereby mules can be rendered immune against an attack of Horse- 

 sickness. This method was first introduced in the Transvaal in 1911 

 and no breeder was allowed to have more than two horses inoculated. 



Out of 445 horses inoculated during that time 46 died or 

 10.8%. This result fully justified a continuation of the method and 

 the next season the death rate was 11.1% in a very severe season 

 when even "salted"* horses died.-'' 



The immunization of mules is now in its eighth year. During 

 1913 out of some 1522 mules that were inoculated only 42 or 

 2.8 percent died. Up to the present time 22.000 have been treated 

 with an average mortality of about 3%. With horses the method 

 has not been quite so successful ; but it has decreased the mortality 

 immensely.-^ 



As soon as this monster disease is held in check or totally 

 stamped out, the future of horse-breeding will be brighter than ever 

 for with a very adequately equipped veterinary department all 

 other diseases are kept within reasonable limits. 



(26) Same as 25 and Becords of Cape Colony No. 389. 



(27) Br. C. Edington ''South African Horse-Sickness" XIII, 1900- The Jour- 



nal of Comparative Pathology and Therapeutics. 

 ( * ) A " Salted ' ' Horse is one that has recovered from an attack of Horse- 

 Sickness and tvas supposed to be immune to future attacks. 



(28) Dr. A. Theiler " Beport of the Tra.nsvaal Department of Agriculture 



1903-4. 



(29) Agricultural Journal of the Union of South Africa 1913, Vol. VI. 



94 



