^ QUATERCENTENARY STUDIES IN PATHOLOGY 



The animal may succumb in this second or convulsive stage, 

 apparently from acute toxic poisoning. It passes into a semi-comatose 

 state, the temperature sinks, and the convulsive spasms become weaker 

 and weaker, preliminary to the fatal termination. 



It should be mentioned that sometimes the animal suffers from 

 diarrhoea with the presence of blood in the rectum. 



Should the disease not prove fatal within a matter of a week or less, 

 then there is every likelihood of its passing into the third stage 

 characterised by the following phenomena : — The convulsive spasms of 

 the limbs, so notable in the second stage, now give place to a condition 

 of more or less complete motor paralysis ; the limbs are outstretched 

 and limp, while, if the sheep be held up by the fleece, they hang down 

 relaxed and listless, and the animal is quite unable to use them for 

 purposes of support. When the feet touch the ground the fetlocks are 

 knuckled under in a perfectly helpless manner. 



Painful sensation, so far as one can judge, does not seem to be 

 affected to any appreciable extent even in this stage, but the reflexes 

 from the limbs appear to be blunted, and in certain cases annulled. 



The whole appearance of the animal closely resembles that of a 

 person suffering from post-diphtheritic paralysis, the nature of the 

 paralysis being essentially motor, and affecting the limbs by preference, 

 although it seems to differ from the diphtheritic form in the fact of the 

 palatal muscles being spared. During the course of the disease the 

 animal is able to swallow liquid nourishment without impediment. 

 The intelligence in this third or paretic stage often remains evidently 

 uninfluenced. The animal recognises objects about it, and will bleat 

 when a companion sheep is removed into a neighbouring pen. It will 

 eat fodder if offered to it, but is quite helpless to seek for such of its own 

 accord, and, as a consequence, in many instances, seems to die from 

 starvation as much as from any other cause. 



In this highly paretic state it may live for weeks, recovery seldom if 

 ever taking place, even although the animal may have been fed artifically. 

 Some subjects of the disease are said to make a partial recovery, 

 probably only one limb remaining permanently crippled. I have always 

 been somewhat doubtful, however, of the diagnosis in such cases ; they 

 look to me more like the effects of spinal abscess, which is very common, 

 at least among lambs, during the spring months. 



(8) 



