380 IOWA DEPARTMENT OF AGRICULTURE. 



that conduce to defective action. Lightness of step appears to be a quality 

 not always dependent upon the conformation of the individual. For instance, 

 length and obliquity of the pasterns are usually said to cause lightness and 

 elasticity of the tread, but do not always do so, for we find many heavy- 

 going horses of this formation. Mechanically this formation should conduce 

 to light-stepping, and does in a measure, but the fact that horses with oblique 

 pasterns sometimes pound, leads us to look for another explanation. The 

 statement may be advanced in explanation that the elasticity resulting from 

 oblique pasterns may be neutralized by a straight shoulder; but this theory 

 will not hold, as one not infrequently finds straight-shouldered, short-pas- 

 terned horses that step lightly. Another explanation has to be found. We 

 have to seek elsewhere in the animal economy than in the peculiar arrange- 

 ment of the bones, muscles, tendons, and ligaments of the limbs to account 

 for the light step of some horses. 



The endowment with this desirable quality is undoubtedly referable to 

 the nervous system, just as speed is. We can not determine the degree of a 

 horse.'s speed by studying his external form. We have to subject him to a 

 test, and so we have in forming a conclusion, as to the degree of lightness 

 or heaviness of his step. 



With regard to labored progression the tendency to it is usually determin- 

 able by an inspection of a horse's conformation. All deviations from the 

 steadily-carried top in the trot, in which there is no rolling, jerking or wad- 

 dling, and from the straight-flexion extension of the fore legs, in which there 

 is no straddling, dishing or winding in, and to the equally straight and easy 

 flexion of the back, can as a rule be determined by an examination of an 

 individual's conformation. The horse with thick or loaded shoulders and 

 wide chest is apt to roll; the one that stands with his fore feet placed wide 

 apart straddles, the knocked-kneed one, as well as the one that toes in gen- 

 erally dishes, while the horse that toes-out winds-in. With the hind legs the 

 cow-hocked horse usually swings his legs in a circumductive manner out- 

 wards. The horse with his hocks wide apart and feet close together "screws" 

 his hocks outwards and usually "plaits." When the hocks are placed be- 

 hind instead of under the quarters there is likely to be a dragging movement 

 of the hind legs. Defective conformation of the legs then shows itself with 

 almosts unvarying regularity in its effects upon the action. 



In order to have the straight undeviating action a horse must flex and 

 extend his legs during progression in a line parallel to the long axis of the 

 body. The knocked-kneed bow-legged or even calf-kneed horse can not do 

 this, and consequently experiences the ill results of loss of time and power 

 in progression. 



Apart altogether from the question of the degree of the lightness or 

 heaviness of the step, the manner in which the feet are placed on the ground 

 has a great influence in determining wear and tear, and is consequently an 

 important point to study. The horse that toes-in usually has the inside 

 quarter of his fore feet defectively developed, which becomes more marked, 

 if he is not rationally shod. The defect of formation of the inner quarter 

 consists in the slanting off of it from before backward and outward and 

 from above downward and toward the center of the foot causing this 

 quarter to assume a wedge-like form, and literally to act as a wedge between 

 the shoe and the sensitive part of the inner quarter, thus predisposing it to 



