72 



The Rot in Sheep. 



however, it would appear to be due to an irregular flow of this 

 fluid from the biliary ducts. The distomata, by their movements, 

 must occasionally form mechanical impediments to the free 

 passage of the bile, leading firstly to its accumulation, and then 

 its sudden flow onwards, when the obstruction is removed, parti- 

 cularly when the parasites locate themselves within the ductus 

 communis choledochus. 



As the disease advances to its fatal termination the breathing 

 becomes short and quick, and is occasionally accompanied with 

 a slight and nearly inaudible cough. (Edematous swellings 

 come on in different parts of the body, especially around the 

 throat and beneath the lower jaw. The accumulation of the 

 effused fluid in this situation is to be explained chiefly by the 

 pendant position of the head of the animal when feeding. 

 There is no surer proof of approaching death than these cede- 

 matous swellings, for they indicate a dropsical condition of the 

 entire system. The prostration of the vital powers day by day 

 increases. The pulse becomes weak, wavering, and indistinct. 

 The animal lies a good deal, refuses all food, is in a state of 

 semi-stupor, and dies from pure exhaustion, as the consequence 

 of general anaemia. 



Peogkess and Dukation. 



Many causes are in operation to influence the rapidity with 

 which the organism of the sheep yields to the influence of rot. 

 Some of these belong to the conditional state of the animal 

 itself, and others to the circumstances by which it is surrounded. 

 Apart from such diseases as may co-exist with rot, the chief 

 of the systemic causes are the number of distomata inhabiting 

 the biliary ducts, the natural stamina of the animal, and its con- 

 dition as to amount of flesh at the time of the declaration of 

 the symptoms. Age also, and the purposes for which the animal 

 is kept, exercise an important influence upon the progress of the 

 affection. Thus breeding* or nursing ewes, from the demand 

 made on their systems for the development or support of their 

 young, will generally succumb more readily than store sheep, 

 and most assuredly much sooner, all other things being equal, 

 than those which are being fattened for the market. Lambs 

 also, when affected in the first few months of their age, for want 

 of sufficiently matured strength of constitution, will soon sink 

 under the malady. 



Among the external or surrounding circumstances few are so 

 potent for good as a continuous supply of food rich in the ele- 

 ments of blood, and containing comparatively a small proportion 

 of water. Sheep thus fed will long resist the progress of the 



