LAMINITIS 



605 



weight. The laminpe are therefore called upon to do far more than their 

 structure is designed for, arid when there is the slightest weakness or ten- 

 dency to inflammation, they are sure to suffer. 



The acute form is generally the result of fast work upon hard roads, and 

 especially liable to it are the fat and over-fed ponies so loved of old ladies, 

 and those of the sporting publican who " corns " his trotter all the week and 

 drives him fast and far on a Sunday. The chronic form is often not sus- 

 pected until irreparable mischief is done, the elasticity of the laminse being 

 destroyed, and the foot having assumed a shape which utterly unfits it for 

 bearing the pressure of the shoe upon hard roads. When the disease has 

 been going on for a long time, the elastic substances between the laminre and 

 the pedal-bone, as well as the fine horny lamin8e between them and the 

 crust, lose the property of extension, and 

 the horn of the crust is secreted by 

 Nature of a more spongy character, and 

 much thicker in substance, than in 

 health. On making a section of such a 

 foot, the arrangement of parts will be 

 such as here delineated in Fig. 104, in 

 which 1 is the os sufFraginis, 2, the os 

 coronas, and 3, the pedal-bone, with its 

 anterior surface separated from that of 

 the crust (7) by a wide space occupied 

 by spongy matter. Here the toe of the 

 pedal-bone projects into the sole and 

 renders it convex, instead of being con- 

 cave, and corresponding with the lower 

 surface of the pedal-bone. 



The laminae and elastic substances 

 between them and their contiguous struc- 

 tures no longer suspend the pedal-bone 

 to the crust, but the weight falls partly 

 upon the sole by means of the toe of the 

 pedal-bone, and partly on the frog, 



which descends so low that in spite of the thickness of the shoe it touches 

 the ground. This descent of the frog is a very marked feature in laminitis, 

 and whenever it is apparent that disease may be suspected. 



But to produce such a marked alteration op form as is here delineated 

 and described takes a long time, and even then it is only in a few cases that 

 the disease reaches to this stage. It will, therefore, be necessary to trace 

 its progress from the commencement, and the effects which are exhibited as 

 it goes on. 



When acute laminitis sets in, there is a considerable amount of fever, 

 indicated by a rapid pulse, usually full and hard, and hurried respiration. 

 It may affect the front feet only, or all four. The animal puts all the weight 

 he can on the heels, and is unable to move. By putting his hind-feet under 

 his body and leaning somewhat backward with an arched loin, he appears 

 to find most relief, and this attitude often leads the attendant to suppose 

 that his back is hurt. If he is made to move, he does so with great diffi- 

 culty, after swaying his body undecidedly. On examining the feet, there is 



Fio. 104.- 



Section of the Foot in Confielied 

 Laminitis. 



1. Os suffraginis. 



2. Os coronaa. 



3. Pedal-bone. 



4. Navicular bone. 



5. Frog. 



6. Sole. 



7. Wall or crust greatly thickened. 



