1080 DISEASES OF THE FOOT. 



the homy laminae become greatly increased in breadth. As the 

 point of the os pedis moves downwards, the horn of the sole at the toe 

 necessarily becomes flattened, and finally takes a convex form. This 

 condition, in connection with certain changes in the horny wall, 

 is termed " dropped sole." It was formerly assumed that the 

 inflammatory growth pressed the os pedis downwards. Dominik 

 insisted, on the other hand, that the horn of the toe was dislocated 

 upwards, but that the os pedis remained in its normal position. 

 Neither opinion harmonises with our present views, and to-day no 

 doubt can exist that Siedamgrotzky's explanation is correct. The 

 continuance of this abnormal form of hoof is dependent on the pressure 

 of the ground against the toe of the hoof whilst the animal is moving. 

 In dropped sole the wall of the toe close below the coronet appears 

 abnormally perpendicular, but near the bearing surface takes a more 

 horizontal direction, whilst the bearing surface itself is not only 

 longer but also more oblique. This abnormal formation of hoof 

 is identified with chronic laminitis. 



Causes. Laminitis is most common in badly -formed, flat, and 

 pointed feet. Its onset is favoured by mechanical irritation of the 

 sensitive structures, resulting from severe work at high speed, long 

 journeys, from continuous standing, as a result of painful lameness, 

 from unskilful shoeing, &c. Rapid work, after prolonged confinement 

 to the stable, is a very common cause of the disease. Laminitis is 

 also very common during and after long sea voyages, as animals 

 can seldom be exercised when in transit, and their digestive system 

 is very apt to become disordered. Chill increases the tendency 

 to the disease, which is therefore more frequent at the time of shedding 

 the coat, after exposure to wet, or after long rest. The external 

 causes comprise errors of diet and chill. Heavy foods, like rye, 

 wheat, and barley, especially when given new, are particularly 

 dangerous ; but new oats and new hay also produce laminitis. At 

 present it is not quite clear how such foods act, but the fact that 

 boiling and steaming seem to diminish the injurious effect, points 

 to the action of a toxin, and contradicts the view that the attack 

 depends on the quantity of normally-digested material which enters 

 the circulation at any one time. Such foods are particularly dangerous 

 to animals which are unaccustomed to them, and which work little. 

 Chills, either from sudden cooling of the body after sweating, or 

 from the consumption of large quantities of cold water, also favour 

 the production of the disease. Finally, laminitis (hematogenous 

 or metastatic) occurs as a complication of colic, during convalescence 

 from influenza, pneumonia, pleurisy, muscular rheumatism, and 



