"TREMBLING," OR LUMBAR PRURIGO, IN SHEEP. • 477 



or on histological investigation, and he considers that they are not by 

 any means present in all cases. 



Besnoit and Morel, who carried out a very remarkable anatomical 

 and pathological study of the disease, used Nissl's staining method, but 

 only found very discrete changes in the cord (vacuoles in the motor cells 

 of the anterior horns). They found, however, significant lesions of 

 neuritis in the peripheral nerves. 



Causation. The cause is as yet little understood, and it is difficult 

 to prove how the forms of neuritis described by Besnoit are brought 

 about. 



The disease was not known in France before the introduction of 

 Merinos, and former investigators referred it to heredity, consanguinity, 

 precocity, and even to sexual excitement. German writers declare that 

 it seems more particularly to attack rams and the better-bred varieties. 

 In reality, the disease occurs in all flocks, and in all kinds of sheep 

 indiscriminately ; it attacks ewe lambs and young castrated lambs 

 as well as rams. Moussu is absolutely of this opinion, and for want 

 of more precise information agrees with Trasbot, and, he believes, with 

 Besnoit, that the symptoms shown may possibly be referred to a 

 chronic intoxication. 



Diagnosis. The diagnosis is difficult during the early stages, but 

 when the pruritus becomes manifest there can no longer be room for 

 doubt. 



Cases of paraplegia might perhaps be mistaken for paraplegia due 

 to coenurosis, but in the latter case there is no pruritus. 



Prognosis. The prognosis is extremely grave, observation having 

 shown that all the patients die after a longer or shorter time. 



Treatment. Until now treatment has proved absolutely useless, and 

 it would seem the best course to slaughter the animals before wasting 

 becomes marked. 



