74 



The Rot in Sheep. 



turnips, but before the month of March there were few of them 

 remaining, and I did not realise as much as defrayed the ex- 

 penses laid out upon the turnips." A result of this kind was to 

 be expected, and forcibly shows the folly of expending money 

 for turnips only as food for rotten sheep in the winter months. 



It is easy to understand that the existence of flukes in the 

 liver being associated with an almost continuous supply of 

 watery or innutritious food, and exposure of the animal to a 

 low temperature and variable weather, will the sooner produce 

 an anaemiated state of system than when the opposite state of 

 things obtains. The entozoa will of necessity drain the blood 

 of its albuminous constituents faster than these are furnished. 

 Besides, their presence within the biliary ducts under such 

 unfavourable circumstances will earlier lay the foundation for 

 those structural changes in the liver itself which unfit it for the 

 secretion of sufficiently pure bile to contribute to the making of 

 healthy blood. Hence an additional cause of the quick progress 

 of rot in the autumn and winter, more especially if wet weather 

 should long prevail. 



In innumerable instances, however, and at other periods of the 

 year, the two chief causes of mischief — innutritious diet and 

 existence of flukes — are not combined sufficiently long for the 

 former to play so important a part as to produce persistent dele- 

 terious effects. We have a good proof of this in those cases of 

 the engendering of rot by the pasturing of the sheep on wet 

 meadows for a limited space of time, and hence we must look 

 to the presence of the flukes themselves, and also to their number, 

 for an explanation of the fact. 



The ill effects attending entozoa of every description are 

 mostly in proportion to their increased number, and not un- 

 frequently also to the importance of the organ in which they 

 are located. A few flukes, by the simple irritation they pro- 

 duce, are frequently non-productive of mischief, at least to 

 any practical extent, in deranging the functions of the liver. 

 Hence the frequent occurrence of sheep, which had been fed for 

 the market, and which had gone on to the perfect satisfaction of 

 their owner, being found to have a limited number of these 

 entozoa in the biliary ducts, the existence of which was not only 

 unsuspected, but would perhaps not have been believed in, but 

 for the circumstance that they were brought to light by the 

 slaughtering of the animal. 



This circumstance is mainly due to flukes, as has been pre- 

 viously explained, not breeding or multiplying within the biliary 

 ducts ; for if the contrary were the case — namely, that young 

 flukes were produced therein, the original few would in due time 

 become the parents of an innumerable progeny. What then, it 



