LOCKED JAW. 81 



in constant motion from the alternate and violent action of the 

 muscles that elevate and depress it. 



Constipation, and to an almost insurmountable degree, now ap- 

 peare. The abdominal muscles are so powerfully contracted, thai 

 no portion of the contents of the abdomen can pass on and be 

 discharged. 



By degrees the spasm extends and becomes everywhere more 

 violent. The motion of the whole frame is lost, and the horse 

 stands fixed in the unnatural posture which he hSs assumed 

 The countenance becomes wilder and more haggard — ^its expres- 

 sion can never be efiaced from the memory of him who cares 

 about the feelings of a brute. The violent cramp of a single 

 muscle, or set of muscles, makes the stoutest heart quail, and 

 draws forth the most piteous cries — what, then, must it be foi 

 this torture to pervade the whole frame, and to continue, with 

 little respite, from day to day, and from week to week ! When 

 his attendant approaches and touches him, he scarcely moves , 

 but the despairing gaze, and the sudden acceleration of the 

 pulse, indicate what he feels and fears 



Tetanus is evidently an affection of the nerves, caused by an 

 injury to some one of them, and the effect of that injury has 

 spread to the origin of the nerve — the brain — and universal dis 

 eased action has followed. 



If the disease terminates fatally, it is usually from the sixth 

 to the eighth day. There are occasionally slight remissions in 

 the spasm, but not sufficiently to enable the animal to eat or to 

 drink. If these remissions return and increase in length, and 

 particularly if there is more relaxation of the lower jaw, there 

 is yet hope. If the horse recovers, it wiU be slowly, and he 

 win be left sadly weak, and a mere walking skeleton. 



On post-mortem examination the muscular fibre will exhibit 

 sufficient proof of the labor which has been exacted from it. 

 The muscles will appear as if they had been macerated — ^their 

 texture wiU be softened, and they will be torn with the greatest 

 ease. The lungs wUl, in the majority of cases, be highly in- 

 flamed, for they have been laboring long and painfu ly, to fur- 

 nish arterial blood in sufficient quantity to support this great 

 expenditure of animal power. The stomach will contain patches 

 of inflammation, but the intestines, in most cases, vidU not ex- 

 hibit much departure from the hue of health. The examination 

 of the brain wUl be altogether unsatisfactory. There may be 

 slight injection of some of the membranes, but, in the majority 

 of cases, there will not be any morbid change worthy of record. 



Tetanus most usually occurs from injuries to some nervous 

 fibre of the foot — sometimes from a prick in shoeing. It is 

 also coniiected with docking, nicking and castration (q. v.) 

 6 d 



