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JOSEPH PLASKETT. 
had affected the nerve centres in the manner I am about to 
describe. But other cases I have seen would seem to indicate 
that we must look to something else as the causative factor. I 
have frequently seen it follow as a result of over-exertion, as, 
for instance, a fatiguing drive on a hot day, especially if the 
animal has been laid up for a few days and is soft and unfit for 
such labors. Again, I have seen two or three typical cases in 
which I could ascribe the cause to nothing else but fretting 
and nervousness. Two, I remember, were brought about by 
separating mares from their offspring and the animals being of a 
highly nervous temperament (both thoroughbred), the worrying 
and excitement in a few hours brought on a typical case of this 
disease. Another case developed during a difficult and pro¬ 
tracted obstetrical case, which required two or three hours time 
and considerable traction to relieve, and during this time the 
mare developed trismus,which rapidly went on to a fatal termina¬ 
tion. And again I have seen cases in which I was utterly at 
sea in finding any cause, as the animals were either at pasture 
or would develop the disease while pursuing their daily work, 
and in both cases surrounded by apparently the same conditions 
as they had been for several weeks. 
I will now attempt to describe the symptoms as they have 
presented themselves to me and as correctly as my memory will 
permit. In some respects this disease quite closely resembles 
tetanus and might be considered as a pseudo form of that dis¬ 
ease. But there are several distinctive differences, and though 
it is nearly always called u lockjaw ” by the laity, it is never 
mistaken for true tetanus by a qualified veterinarian. I have 
never seen a case until after the disease had made some progress, 
but according to reports the first symptom noticed is a general 
uneasiness, which manifests itself by restlessness, and is quickly 
followed by a profuse perspiration. Almost from the first tris¬ 
mus is present to such a pronounced degree that severe muscu¬ 
lar efforts are unable to prize the jaws apart. Sometimes a 
careless owner’s first intimation that anything is wrong is that 
after a hard drive on a hot day he is unable to get the bit out of 
