Animal Diseases. ^^i 



On infested farms the niortaliis during the summer season is 

 ver} high, but no unnatural mortality had occurred on this farm during 

 the past ten years at least. 



The material used for purposes of infection was the blood taken 

 from animals dying of the disease at Koonap and at Somerset East. 

 The blood was either simply defibrinated or mixed with a small 

 quantity of a solution of neutral citrate of potash. I was unable to 

 tnid that either had anv advantage over the other as an infecting 

 agent. 



Subcutaneous injection of doses as large as 40 c.c. almost al- 

 ways failed to produce death, although some oscillation of the tem- 

 perature of the inoculated animals was observed. 



Intravenous inoculations of doses up to 30 c.c. were uncertain. 



Where the animals inoculated in this way developed the disease 

 and died, there was no certainty that their blood would produce the 

 virulent disease in others. Failures have occurred even with the 

 injection of 100 c.c. into the jugular vein. 



In some cases blood which was drawn from inoculated animals, 

 which did not themselves die, proved capable of setting up the 

 virulent disease in others. 



As further indicating the parado.\ical nature of the malady I 

 may add that in by far the greater number of these goats which had 

 resisted inoculation it was proved that an inoculation of even a much 

 smaller dose of blood at a later date or exposure of the animals in 

 an infested veld was attended with the production of the malady 

 followed by death. 



I felt, therefore, that these goats, which largely resisted infection, 

 although being not immune, had acquired what one might term a 

 modified resistance or acclimatization. 



This is the more probable from the following circumstance. Mr. 

 Thomas Hoole. a well-known breeder at Highlands, made a ],)urchase 

 of a considerable number of goats fn^m a district of Somerset where 

 the disease is known to l)e absent. After purchasing he sold part to 

 Mr. L. White, whose farm lies many miles distant. .\fter these 

 goats had been placed on the respective farms thev liegan to die of 

 Heart -water, while contrarily the animals belonging to the place did 

 not die. (3n both farms Heart-water occurs. 



I may further add that the ordinary Boer goat is practically in- 

 su.sceptible to the malady, and that the pure bred Persian goats pos- 

 sess " high degree of insusceptibility to natural infection. 



In some parts where the disease only occurs to a slight extent 

 I have had it reported to me by the farmer as Ijeing flail-sickness, 

 thus called as the gall bladder is often very much distended with bile. 



Since that time I have imported all goats by train from a clean 

 area in Somerset and in these animals I have found it much easier 

 to keep up a strain of infection from animal to ajiimal. 



Still, however, inoculation frequently fails and I fell constrained 

 to report to my Government that goats evidently were not the proper 

 animal host for the contagium of this mala<lv. 



in sheep the conditions are practically the same. 



