338 THE EXTERIOR OF THE HORSE. 



Seam of the bars affects the latter and breaks their continuity. This is one 

 of the accidents of the foot most rebellious to treatment. 



We will also say, in this connection, that seams or cracks are sometimes con- 

 cealed, in animals offered for sale, either by a coating of gutta-percha, putty, wax, 

 or simply hoof ointment. They are called barred when, as a means of treatment, 

 their borders are approximated by the aid of special iron clasps. 



Corns. Corns are contusions of the sole in the region comprised between 

 the wall and the bars. They are common in feet with low and weak heels, 

 especially in contracted feet. 



They are called dry when the horn which covers them is of a yellowish 

 color and stained with blood. 



A corn is moist when the exudation of blood and serum, in consequence of 

 the bruising, is more abundant, renders the horn softer, and even separates it 

 over a small area from the tissues below. 



Finally, it is called suppurating whenever the alteration, not confined to a 

 simple ecchyrnosis, has occasioned inflammation and suppuration of the subjacent 

 tissues. 



Bruised Sole. Bruised sole is an accident of the same nature as that 

 of corns. It only differs from the latter in that it consists of a contusion of a 

 more or less large area of the sole at the quarters or at the toe. According to the 

 objective characters of the horn, it is also qualified dry, moist, or suppurating. 



Concussion of the Hoof. Ancient veterinarians have designated under 

 this name a localized congestive state of the keratogenous membrane of the foot 

 resulting from external violence, most frequently the blows of the farrier's 

 hammer. 



This alteration differs only from that of laminitis in that it is due to the 

 influence of purely local causes. Anatomically speaking, they are identical. 



Laminitis. Laminitis (founder) is, primarily, a congestion of the kerato- 

 genous apparatus in the region of the toe and the mammae. 



Under the pressure of the serous and sanguineous exudation which results 

 therefrom, the podophyllous tissue (flesh of the foot}, tightly compressed between 

 the wall and the third phalanx, becomes extremely sensitive, which obliges the 

 animal to walk upon the heel, or even renders all support by the foot impossible. 

 The founder, in this case, is called acute, for it is accompanied by phenomena 

 generally very intense. 



If the temperature fall, the symptoms ameliorate, and inflammatory phe- 

 nomena gradually invade the tissues pre- 

 viously congested, the keratogenous mem- 

 brane, at this level, becomes the seat of 

 an abnormal and exaggerated secretory 

 function, characterized by a profound de- 

 formity of the hoof and a decided altera- 

 tion in the form and relation of the inter- 

 nal osseous structures. It is this which 

 FIG. 123. constitutes chronic founder or laminitis. 



The foot, in such cases, assumes an 



oval form and the wall is decidedly rammy ; its toe acquires an enormous thick- 

 ness and becomes convex ; its heels are high and touch the ground first in loco- 

 motion. The sole, compressed by the plantar border of the third phalanx, loses 



