« NOTE BY I\TTl, SPOONER. 315 



Having given the leading symptoms attending the disease, it wouM be 

 •well perhaps, here to mention tiie morbid aj)pearince.s of the joint wliich ac- 

 company tliem, and which post-mortem exainiiiatitnis of the mahidy in its 

 different stages, exhibit. Among some morbid specimens in my possession 

 one merely shows a slight indentation on the ridge of the navicular-bone, and 

 *vhen recent the corresponding portion of the smew was loughened. The 

 horse had pointed a long time prior to his death, and was lame for a mile or 

 so on tirst going oif. 



Another specimen exhibits holes in the navicular-bone somewhat like a ca- 

 i'ious tooth, together with very diminutive bone deposits on different parts 

 of the. surface of the bone. Tlie mare to which it had belonged had been 

 lame for several years in both feet, wliich were much contracted, and got 

 gradually worse until she was otdy tit to go to plough. 



Another case developes still greater disease on both navicular-bones, 

 ■which are ulcerated in a great degree, and present also numerous long spiculi 

 on their corticular surface, besides which there is an ossitication of the infe- 

 rior cartilage, so that although the bones have been boiled the navicular- 

 bone rests securely on the ossified parts, which must therefore have materi- 

 ally saved the diseased tendon. The bones had belonged to a very old horse 

 and favorite hunter, that had been lame for many years, and had conse- 

 quently been u--ed for agricultural labor. 



Another morbid specimen is that of the feet of an old horse that had been 

 groggy for some years. The navicular bones in both feet were closely united 

 to the riexor tendons, and on tearing them apart the fibres of the sinew were 

 lacerated ; the greater part of the posterior surface of these bones was de- 

 nuded of cartilage, and presented a rough appearance, and the bones them- 

 selves Avere situated higher up in the hoof tlian natural, asbuming a morf 

 vertical or less horizontal position. Although this was the position of the 

 bones, yet the foot by a common observer would have been pronounced 

 well-shaped ; the sole, however, I found enormously thick. 



From a review of the various circumstances which attend the domestica- 

 tion of the horse, we may, 1 think, justly conclude that most of them operate 

 in inducing the disease in question. The foot in its natural state has a cUs- 

 position to contract when at rest, and expand when pressed upon. In a 

 weak foot there is a greater tendency to spread than contract, but in a strong 

 one we may consider these two antagonist principles as equivalent to each 

 other. When, however, the horse becomes domesticated, every means is 

 used to aid the contraction and to neutralize the disposition to expansion. 

 The shoe is nailed to the foot when the latter is in its most contracted state, 

 and the horse is confined in a stall the greater part of the day. On a 

 sudden he is taken out of the stable, and, without having prepared his joints 

 and limbs by preliminary exercise, he is driven as fast as he can trot for the 

 space of an hour or upwards, on the hard roatl, and then during the remain- 

 der of the twenty-four hours consigned to the stable. What is the result of 

 this unnatural system ? By the joint eifects of the shoe, hot litter, an' 

 standing in the stable so long, the foot so contracts that the sole is dr' a 

 upwards, and with it the navicular-bone, which thus, as we have befo- no- 

 ticed, has a hard unyielding substance to rest upon ; and the joint saving 

 been in a quiescent state for many hours, there is probably a dimini^hed se 

 cretion of synovia (joint oil). In this unprepared state the feet are batterea 

 on the hard road,* and the result is in many cases a bruise of the synovial 

 membrane, which may either be sufficient to produce sudden and severe 

 lameness, or so moderate as to occasion the slightest lameness only. 



* The reader will bear in mind that Mr. Spooner speaks of the Iwd metal roads of 

 England. Our roads, hard only >fvhen they are dry, do not produce these effects in a a<? 

 groat degree.— Am. Ed. 



