282 BUREAU OF ANIMAL INDUSTRY. 



of the condition of vital integrit}', which is simply but comprehensively 

 expressed by the terms health and soimdness. 



But let some change, though slight and obscure, occur among the 

 elements of the case; some invisible agency of evil intrude among the 

 harmonizing processes going forward; any disorder occur in the rela- 

 tions of cooperating parts; anything appear to neutralize the efficiency 

 of vitalizing forces; any disability of a limb to accept and to throw 

 back upon its mate the portion of the weight which belongs to it to 

 sustain — present itself, whether as the effect of tra,umatic accidents or 

 otherwise; in short, let anything develop which tends to defeat the 

 purpose of nature in organizing the locomotive apparatus, at once we 

 are confronted hy that which may be looked upon as a cause of lameness. 



Not the least of the facts which it is important to remember is that- 

 it is not sufficient to look for the manifestation of an existing discord- 

 ance in the action of the affected limb alone, but that it is shared by 

 the sound one, and must be searched for in that as well as the halting 

 member, if the hazard of an error is to be avoided. The mode of action 

 of the leg which is the seat of the lameness will vary greatl}^ from that 

 which it exhibited when in a health}' condition, and the sound leg will 

 also offer important modifications in the same three particulars before 

 alluded to, to wit, that of resting on the ground, that of its elevation 

 and forward motion, and that of striking the ground again when the 

 full action of stepping is accomplished. Inability in the lame leg to 

 sustain weight will imply excessive exertion by the sound one, and lack 

 of facility or disposition to rest the lame member on the ground will 

 necessitate a longer continuance of that action on the sound 'side. 

 Changes in the act of elevating the leg, or of carrj'ing it forward, or 

 in both, will present entirely opposite conditions between the two. 

 The lame member will be elevated rapidl}', moved carefully forward, 

 and returned to the ground with caution and hesitancy, and the contact 

 with the earth will be effected as lightly as possible, while the sound 

 limb will rest longer on the ground, move boldly and rapidly forward, 

 and strike the ground promptly and forcibly. All this is due to the 

 fact that the sound member carries more than its normal, health}^ share 

 of the weight of the body, a share which may be in excess from 1 to 

 250 pounds, and thus bring its burden to a figure varying from 251 to 

 500 pounds, all depending upon the degree of the existing lameness, 

 whether it is simply a slight tenderness or soreness, or whether the 

 trouble has reached a stage which compels the patient to the awkward- 

 ness of traveling on three legs. 



That all this is not mere theory, but rests on a foundation of fact 

 ma}" be established by observing the manifestations attending a single 

 alteration in the balancing of the body. In health the support and 

 equilibrium of that mass of the body which is borne by the fore legs 

 is equalized, and passes by regular alternations from the right to the 



