616 VETEEINAEY HYGIENE 



free from ticks by baths, such as have been previously 

 described (p. 422). 



The veterinary authorities in Cape Colony, especially 

 Mr. Spreull, have been working for some time to devise a 

 means of protective inoculation against heart-water, and 

 the work in this direction is hopeful. 



EPIZOOTIC ABORTION* 



The animals affected by this are the cow, mare, and ewe ; 

 in the former, and probably in all, an organism is at work, 

 though not necessarily derived from a previous case of 

 infection. There is evidence to show that sporadic out- 

 breaks may occur independent of contagion as their starting 

 point, the organism responsible for the trouble having been 

 leading a saprophytic existence outside the body, probably 

 in the soil. 



The organism isolated by Bang in epizootic abortion of 

 the cow produced the disease in 87 per cent, of the animals 

 experimented upon ; pure cultures of the organism isolated 

 by him produced abortion whether injected into the veins 

 of cows, mares, and ewes, or merely placed in the genital 

 passage. The effect of the introduction of this organism 

 was to produce an infectious metritis. 



Though soil infection is not unlikely as a starting point, 

 it is probable the disease is more frequently introduced into 

 a herd or stud by an apparently healthy though really 

 affected animal. A bull, for instance, which has served an 

 infected cow, is for some time capable of infecting others. 

 A stallion which has suffered from influenza may be the 

 means of causing abortion in the mares he serves for many 

 months after his apparent recovery. 



■■'■ This section is based on the following published papers : ' Abortion 

 in Cattle,' Prof. Brown, C.B., Journal of the Boyal Agricultural 

 Society, vol. xi., p. 4, 1891 ; ' Epizootic or Contagious Abortion,' Prof. 

 McFadyean, idem, vol. Ixii., 1901 ; ' Management of Aberdeen Angus 

 Cattle,' C. Stephenson, F.E.C.V.S., idem, vol. v., 3rd series, part i., 

 1894. 



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