80 



The Rot in Sheep. 



emaciation and death of the animal, without regarding the 

 distomata as an additional cause in producing a continued drain 

 on the system of the sheep. 



To return to our description of the autopsy. The viscera of 

 the chest, in common with every other organ of the body, give 

 evidence of anaemia. Within the thoracic cavity serous effusion 

 is met with, which, however, is mostly devoid of colour, limpid, 

 and transparent. In quantity it is considerably less than that 

 existing within the abdomen. Little or no fat is present about 

 the heart ; and that which does exist is of a slightly yellow 

 colour. The walls of the heart are flabby and pale. The blood 

 contained in its cavities, as well as that in the large venous 

 trunks, is watery and imperfectly clotted. The lungs, apart 

 from other morbid changes which may co-exist with rot, do not 

 present any special lesions. Like other parts of the organism, 

 however, they give evidence of general pallor. In the chapter 

 of this Essay on the pathology of rot, we have fully discussed 

 the opinion of Mr. Blacklock as to the malady being a tuber- 

 culous one of the lungs ; and as such it is not necessary to repeat 

 our arguments in opposition to his statement. 



The condition of the brain and its meninges agrees with that 

 of the body generally. A larger amount of fluid than ordinary 

 is present in the ventricles of the brain, and the vessels of the 

 meninges are indistinctly seen in consequence of the watery 

 character of the blood within them. 



Such are the general post-mortem appearances of rotten sheep. 



We have, however, many proofs that affected sheep often die 

 long before this general break-up of the organism is accom- 

 plished. This is particularly the case at the commencement of 

 winter, and on the occurrence of white or hoar frosts. Such 

 animals often sink from passive congestion of the lungs or liver, the 

 tendency to which is given by the altered condition of the blood 

 from a change in the relative proportion of its several con- 

 stituents. Dr. Carpenter and other physiologists rightly remark 

 that a diminution of the specific gravity of the blood, from a loss 

 of its saline and albuminous materials, predisposes to haemorrhage, 

 congestion, &c. ; and such we have shown to be the condition of 

 this fluid comparatively early in the disease. The lungs in these 

 cases are red throughout, being charged with blood. They are 

 also heavy to the feel, and portions of them will be found to sink 

 in water. The vessels of the pleura and pericardium are like- 

 wise overloaded with blood. The liver, however, is mostly of a 

 dark colour, not throughout, but in patches of various dimen- 

 sions. The flesh of such animals is of fair colour and tolerably 

 firm. Some fat also, not much changed in consistence, exists 

 around the kidneys, and in other places of its ordinary deposit. 



