ABORTION IN COWS. 



There is good reason to believe that prolonged lactation during 

 pregnancy is, in young stock especially, a fruitful source of the mishap 

 in question. It is the custom with many farmers and dairymen to 

 milk pregnant cows through nearly the whole period of gestation. The 

 intimate physiological relationship existing between the mammary 

 gland and the uterus, is either not understood by them or altogether 

 lost sight of, and the debilitating influence of lactation under advanced 

 pregnancy is altogether disregarded. 



A common observation will suffice to show how forcibly and de- 

 liberately these two organs act and react on each other. When 

 after calving the 'foetus is allowed to suck the dam, the latter is now 

 and again observed to pass through a brief paroxysm of uterine con- 

 traction or straining. In a less degree this uterine excitement is also 

 induced by the hand when cows of an excitable temperament, far ad- 

 vanced in pregnancy, are being milked. It cannot be insisted that this 

 exalted sensibility of the uterus to outside impression belongs to all 

 .cows alike, nor can it be said to endure in many after the first or 

 second pregnancy ; nevertheless, our experience enables us to place it 

 in the rank of occasional causes of abortion. 



The double tax demanded by the foetus on the one hand, by the milk 

 pail on the other, is, when continued over a certain period, a per- 

 nicious burden under which many cows fail to carry the fruits of con- 

 ception to the final stage. It is no argument in -favour of this theory, 

 however, to say that prolonged lactation is the sole cause where, as 

 elsewhere shown, a single case of abortion is sufficient to upset an 

 entire herd. 



The causes of abortion are not only numerous, but diverse both in 

 regard to their nature and mode of action. Sometimes they are very 

 obscure, and difficult to trace to their source ; at others they are easily 

 recognised and understood, while some are so subtle and inscrutable 

 as to evade the most searching inquiry into their origin. It frequently 

 happens that without any appreciable departure from a long estab- 

 lished system of general management and care, and without any de- 

 viation from sound principles of hygiene and sanitation, without any 

 fresh importation of stock, and in the entire absence of sickness from 

 the herd, abortion appears in its worst form, and baffles the skill of 

 the most earnest and painstaking investigator to throw light on the 

 causation of the disorder. 



Abortion in bovines is pretty generally admitted to be more fre- 

 quent, and the consequences much more serious, than they were in 

 early times, and any inquiry having for its object an elucidation of 

 the cause of the disorder must embrace these facts, and we must en- 

 deavour to formulate the conditions on which they depend. 



As already stated, the causes by which abortion is induced are very 

 numerous and various. A large number of them have their origin, 

 and exercise their influence, outside the body, while others, although 

 originating from without, require to be introduced into the economy, 

 in one direction or another, before any untoward result can arise. On 

 the other hand, many conditions conducive to the accident, and which 

 may either be of a temporary or permanent character, arise within 

 the body of the animal itself, and it may be in the embryo which it 

 carries and nurtures, through the influence of the bull. We recognise, 

 therefore, in the category of causes, some that are extraneous, and 

 others that are intrinsic. Of the latter some are parental, others 

 foetal. It may be also said that the foetal membranes or placentae, 

 which are decidous and belong as much to the foetus as the dam, are 

 sometimes the seat and origin of the disturbing cause. Of the external 

 causes, not a few have their origin in force applied to the body of 

 the pregnant cow, which takes various shapes and is applied in many 

 directions. 



