198 PATHOLOGY OF GESTATION, 



when the foetus is expelled before the ordinary period for parturition, yet 

 with all its organs sufficiently perfected to enable it to exist for at least 

 some time in the external world, this is designated //'^/^^////'^ birth (^partus 

 prcEinaturtis). In the first instance, the young creature is either dead when 

 expelled from the uterus, or dies immediately afterwards ; and in the second 

 it may be weakly and immature, and succumb after a variable period ; or 

 it may continue to live and thrive. In practice, there is no accurately 

 defined limit between abortion and premature birth, and especially when 

 the latter has been brought about by some of the causes which produce 

 the former. 



Abortion may be said to take place in solipeds, when the foetus 

 is expelled forty days before the normal period ; in the bovine species, 

 thirty-five days ; in the Sheep and Goat, twenty days ; in the Pig, fifteen 

 days ; and with the Bitch and Cat, seven days. Saint-Cyr says that it 

 may be acknowledged that abortion has taken place, when the foetus is 

 expelled in the Mare before the 300th day of gestation, in the Cow before 

 the 200th, in the Sheep before the 140th, and in the Pig before the looth 

 day. 



There is not the same tendency or readiness in all the domesticated 

 animals to abort. The Bitch and Cat rarely do so, even after serious 

 injuries ; and the Pig retains its foetuses almost as tenaciously \ but the 

 Sheep and Goat are rather liable to this accident. The Cow and Mare, 

 but more especially the former, most frequently lose their foetus. In 

 what proportion abortions occur is not ascertainable from any document- 

 ary evidence. For the Cow, Baumeister and Rueff state that in France, 

 in a dairy containing Durham Cows, and numbering 100 pregnancies, 

 there were 17 abortions ; and at Hohenheim, from a register kept for 

 thirty years, it appears that one-fifth of the Cows aborted. Among 5864 

 Sheep of various breeds at the same establishment, there were only 26 

 abortions, or o'433 per cent. 



Abortion may occur at any period of gestation within the limits above 

 named, though it is much more frequent during the first than the second 

 half of pregnancy, and especially with the Mare. When this accident 

 occurs at a very early stage, it may produce no appreciable disturbance 

 of health in the female, iind the ovum escapes intact, and often unper- 

 ceived. The accident is more serious when it happens at a late period ; 

 as it then not only causes the loss of the young animal, but may compro- 

 mise the existence or value of the mother. 



Abortion may be either sporadic or eiizootic or epizootic. When cases 

 occur here and there over a wide extent of country, without any relation- 

 ship as to causation, they are sporadic or accidental abortions ; and 

 though they must be reckoned as losses, yet they rarely attract much 

 attention from the damage they inflict, and because of their isolated, and 

 by no means unusual, occurrence. But when, on the contrary, the 

 pregnant animals — say Cows, Ewes, or Mares — on a farm, in a village, or 

 over a large district or country, miscarry in large numbers, and the mishap 

 is evidently due to the same cause or causes, then it is indeed a grave 

 misfortune, as it entails serious damage — present and prospective — to the 

 interests of agriculture. This is enzootic or epizootic abortion : an occur- 

 rence far from uncommon, and the etiology of which has attracted the 

 attention of the most distinguished European veterinarians for many 

 years. 



