304 DADK'S VETERINARY MEDICINE AND SURGERf. 



the (a. Knqss of the hoof, and produces lesion of the sensitive parts 

 underneath the horn, giving rise to some little hemorrhage :'n the 

 first instance, and subsequently to more or less inflammation — 

 occasionally, even to suppuration, depending, of course, on the 

 extent and nature and duration of the lesion, as well as on any 

 treatment, or aggravation from non-treatment, it may have re- 

 cc ived since being occasioned. When the crack does not extend 

 through the substance of the wall — which it sometimes does not 

 at first, though it may do so afterward — it may be said to be non- 

 penetrant; and this, when it happens, seems to be referable to 

 a sort of natural fusion there certainly exists between the solid 

 horn, as it descends from its secreting gland, (the coronet,) and 

 the horny laminae (new matter), which become glued to it in its 

 course downward. It. is in this uniting horny medium that seedy 

 toe commences and progresses. 



Lameness is the usual accompaniment of penetrant sand-crack, 

 but not the invariable one. When penetrant it is said to arise 

 from the sensitive laminae getting pinched between the sides of 

 the crack. However this may be, inflammation following the 

 lesion has certainly its share in causing pain during action. In 

 general, the lameness does not amount to much, nor is it of long 

 duration, provided the sand-crack receive proper and timely at- 

 tention ; but if the crack is not heeded, action of the foot will much 

 aggravate the malady, and end in lameness increased so much as 

 to forbid further use being made of the animal. 



Toe Sand-crack. 



Occurring in the hind foot, as this crack almost invariably 

 does, occupying a different situation in the hoof, and arising alto- 

 gether from a different cause, toe sand-crack may be regarded as 

 almost a distinct affection. 



The subject of it is not the light horse, but the heavy one --the 

 cart and wagon-horse, the dray-horse, the latter especially; aud 

 in particular, I believe, in paved cities, they are the sufferers from 

 this disease. I say ' sufferers,' because it is only those veterinary 

 surgeons whose practice lies among horses of this description that 

 have any conception of the amount of pain and irritation with 

 which sand-crack — simple as it may seem to those who are in the 

 habit of meeting quarter crack only — is found to be accon ;onied. 



