427 



a thin, slightly adherent horn that bears but little or no wear. The 

 sole being now convex, the diseased, tissues are compelled to })ear 

 unusual weight by coming in contact with the ground, and hence it 

 is these animals are generally incurable cripples. In the majority of 

 cases wliere the sole is raised to meet the pedal l)one and pumiced sole 

 occurs, it is due not to pressure of the bone from within (for the tis- 

 sues are capable of adapting themselves to the gradual change), but to 

 impaired vitalitj' of the sensitive tissues from the inflammation and 

 tlie constant concussion and pressure a|)j)lied from without during pro- 

 gression. Added to this is to bo considered the paring away of the 

 horn by the smith wh<Mi applying the shoe, thereby keeping the sole 

 at this i)oint too thin. 



Tifiintuj up of the toe. — In man}' cases of laniinitis which have 

 become chronic it is found that the toe of the foot turns up, and that 

 the heels are longer than natural, while the whole hoof next to the 

 coronary band is circled with ridges like the horn of a ram. Even in 

 other cases where recovery has taken place, and in other diseases 

 than laminitis, these may be found in the wall of the foot, but in 

 these cases the ridges are equally distant from each )ther all around 

 the foot, while in turning up of the toe the ridges are wide apart at 

 the Iieels and close together in front, as seen in the figure (Plate 

 XXXI, Fig. 4). These ridges are produced by ijeriods of interference 

 with the growth of horn alternating with periods during which a nor- 

 mal or nearly normal growth takes place. When the toe turns up it 

 does so because the coronary band in front produces horn very slowly, 

 while at the heels it grows much faster. 



Animals affected with pumiced foot and turning up of the toe dur- 

 ing progression always place the abnormally long heel first upon the 

 ground, not because the heel is too long, nor as in acute or subacute 

 laminitis to relieve the i)ain, but for the simple reason that the animal 

 carries the leg forward \vith the column of bones in the normal posi- 

 tion, and attempting to keep them so the heel first comes in contact 

 with the ground, and lie then knuckles over at the fetlock in propor- 

 tion to the amount of foot deformity present as he brings the toe to 

 tlu^ surface. 



Tlie pain and impairment of function in these cases always result 

 in marked atrophy of the muscles of the forearm and shoulder, and 

 to some extent of the pectorals, while the position of the fore feet 

 advances the scapula joints so far forward as to cause a somewhat 

 sunken appearance of the chest in front, which the laity recognize 

 as a peculiar form of the disease popularly designated as "chest 

 founder." 



Regarding the presence of inflammation during this process, tliere 

 is no doubt a chronic form exists a long time after these lesions com- 

 mence, yet it may in time subside and leave the feet free from fever 

 while the other changes still cro on. 



