^37(i DISEASES PECULIAR TO SOUTH AFRICA 



Heart-Water in Sheep and Goats 



What It ISi Heart-water is an inoculable disease due to a micro- 

 organism so minute as to defy the efforts of all investigators to find it. 

 Like the organism of horse sickness, it passes through all filters, though 

 Theiler reports it did nut pass through a Berkefield or Chamberlain filter, 

 and he hopes very soon to be able to define it. 



After inoculation of blood from a sick animal into a healthy one, 

 it is found that from five to fifteen days elapse before any symptoms ap- 

 pear, and usually the time is from eight to ten days. After the mani- 

 festations of symptoms the disease runs on from two to six days, or even 

 more. Heart-water in sheep is very similar to, if not identical with, 

 the Heart-water of cattle, and can be transmitted by blood inoculation 

 from sheep to goats and to cattle, or vice versa. The credit of these 

 investigations is due to the late Dr. Hutcheon and his assisstants and to 

 Mr. Loundsbury, the Cape entomologist who has made clear the mode of 

 spreading and dissemination of the disease. 



Heart-water is met with only in the bush veldt, on which the breed- 

 ing of high bred sheep and goats is distinctly disappointing. One happy 

 feature about this disease is, that not all the bush veldt is equally bad. 

 The worst parts are certainly the low lying. The season has some in- 

 fluence. In summer the disease is more prevalent and virulent, and 

 the wise farmer knowing this, when a outbreak occurs among his flock, 

 if on a low veldt, moves the sheep to a higher veldt. The disease soon 

 comes to a standstill. It is not contagious, for once a flock was moved 

 out of the Heart-water veldt to a high and noninfected area, and mixed 

 among other sheep and goats, the latter would not take the disease. 



Mode of Infection! Mr. Loundsbury, the Cape entomologist, found 

 that Heart-water is carried by a certain species of tick, viz., the Bout tick, 

 and, in his experiments, time after time, produced the disease artificially. 

 He reports that the disease does not go from the female through the egg 

 as is generally supposed, but is taken up either by a larva or lymph from 

 a sick animal and so communicated, thus showing that while the disease 

 is not contagious it is infectious. 



The Bout tick breeds only in warm veldt where it finds protection 

 in the bushes. 



Heart-water is met with in the Transvaal 0. R. C, C C, and 

 Rhodesia, and in fact any part where the Bout tick is found. 



How To Know Itt Fever accompanied by rise in temperature, may be 

 the only symptom, and the animal suddenly dies, although it might have 

 seemed quite healthy only a short time before. Usually, however, the 

 temperature continues to rise even up to 106 degrees F, or 108 degrees F, 



