438 



DISEASES AND THEIR TREATMENT. 



Fig. 753. — Inferior Articulating Surface of the Navicular 

 Bone in a Healthy Condition. 



step or jump the horse takes, strains the tendons, or causes inflammation. By con- 

 traction, because in proportion to the drawing together of the heels, there will be a 

 compressing or forcing upward of the arches of the commissures and horny frog 

 against the tendon and navicular joint, impeding the action of the joint generally, 

 and liable to cause inflammation of the synovial membrane, ulceration, and change of 

 structure ; it also destroys the natural position of the limb, by making the pastern 

 Joint more perpendicular, which, as has been mentioned, increases the jar of the co- 

 ronary on the pedal bone. So that we have involved the lower surface of the navic- 

 ular bone, its synovial membrane, the flexor tendon which plays over it, and some- 

 times the upper surface, when it is called coffin or navicular joint lameness. 



All leading authorities 

 concur in the correct- 

 ness of this statement. 



Treatment. — The first 

 and most important con- 

 dition of cure is rest; 

 the horse should be at 

 once taken from all 

 work ; he must not be, 

 as is commonly the case, 

 allowed to run even ' in 

 pasture, or anywhere 

 where there would be 

 any freedom to run or 

 walk around much ; give 

 him simply the limits 

 of a large, level stall. 

 Remove the shoe by 

 raising the clinches, and 

 pull out the nails one by 

 one ; then cut off or 

 hammer down the toe- 

 calk, and partly turn up 

 the toe like the ground 

 surface of an old worn-out shoe. Next, raise the heel-calks from 

 five eighths to three quarters of an inch, fit the shoe nicely to the 

 foot, and nail on, being careful hot to wrench or hammer it un-; 

 necessarily in doing so. Two important points are gained by this : 

 First, raising the heels from the ground throws the articulation of 

 the pastern bone well forward upon the pedal bone, relieving press- 

 ure of the navicular bone from the tendon supporting it ; second, 

 the removal of all pressure of the frog from the ground, which ag- 

 gravates the inflammation, and rounding the toe aids mobility, and 

 thereby lessens the strain upon the joint. 



Pig. 754.— Indications of Disease. 



Fig. 755.- 



-Inflammation Progressed so Far as to Cause 

 Caries of the Bone. 



