STONES (calculi) and other concretions of various kinds, are every now and then met with in the in testinal canal. They are more commonly found within the large guts. These substances differ in composition, magnitude, and shape. Some are purely calcareous; others are resolvable into what appears to be nothing more than collections of har dened faces. Their form and size seem to be regu lated principally by the situation wherein they are lodged; at times, however, it is clearly determined by a central nucleus: a horse-nail, e. g. has in seve ral instances, from having been swallowed accident ally, become the nucleus of a calculus, which in form has precisely resembled it. There is a calcu lus into whose composition hair enters largely; but this is met with in neat cattle more especially, ow ing to the habit cows have of licking their own hides, and swallowing the hair. The majority of intestinal calculi are white.
We shall have no difficulty in accounting for the formation of calculi within the guts, when we come to know that the horse, under certain circum stances, is an animal that will absolutely lick up and eat the very earth he treads upon: craving horses in confined situations, with an insufficient supply of provision, will, for the want of more food. pick up dirt, gnaw rails, and be apt to destroy or consume almost any thing within their reach; and in this way they lay the foundation in their insides for concretion. Independently of this, however, we are to bear in mind that most horses do necessarily consume a quantity of dirt with their food: millers' horses in particular are subject to calculus, in con sequence of the meal they are fed upon containing particles of the grindstones. We know of no symp toms unerringly denoting the presence of intestinal calculus; and even were we certain about its exist ence, have we any thing feasible to propose by way of remedy.
Worms. Four kinds of worms have been disco vered within the bowels of horses; the bot; the the long, round, white worm; the thread-worm; and the The BOT is an inhabitant natural to the stomach: now and then we rind some in the adjoining intestine; but we never detect any resi dent either within or near to the large guts. Pro perly speaking, the bot is not a worm at all: it is simply the larva or caterpillar of the gad-fly, bear ing the same relation to the fly itself as the silk worm does to its moth. This renders its natural history very curious. Every groom knows that it is only at a certain season of the year that horses void hots; on the other hand, every veterinarian is aware that, although none are expelled, boss exist in the stomach all the year round. The ex planation of these notorious facts is this. At the latter end of the summer, the time when horses are teased most by flies, the gad-fly makes his ap pearance, of all the tribe the most formidable; the female of which insect it is that especially haunts the horse in order that she may deposit her eggs somewhere upon his coat. By the act of biting or licking themselves, which horses are prompted to from the bite of the fly, it appears that the eggs are transported upon the tongue, and thence pass, probably with the food, into the stomach; where, from heat and moisture, they become hatched, and give origin to a small active worm which grows by the ensuing summer to a hot. About June, having completed its growth, it becomes expelled from the body with the dung, in which it lies en veloped upon the ground, whilst it again changes its state by becoming a chrysalis or grub. It has yet to undergo its last transformation in the series, viz. that into a fly, which takes place after it has
lain a few weeks in the dung. Of the newly cre ated flies, the males seek their mates; the female, as soon as they have become impregnated, range in search of a horse upon which she chooses to de posit her eggs.
For what wise end or purpose the stomach of a horse was made the nidus for an animal of such apparent insignificance as the hot, we shall not pre tend to divine: we have no proofs that they do any harm there; neither can we take upon ourselves to say that they are productive of good. The mu cus of the stomach appears to furnish them with aliment; but the little they must consume cannot render it of much importance, one would think, whether it be that or the alimentary matters them selves. The complaints of grooms and others, therefore, about their destructive effects appear to be totally devoid of foundation. It is this impres sion of their pernicious agency that urges people to feel desirous to have them got rid of: the truth of the matter is, however, that in consequence of the hot having two hooks by which it clings fast to the lining of the stomach, we have no means of effecting this, even though it were really necessary; we can, certain enough by administering a dose of purgative medicine at the season when we see them voided, cause them to be expelled quicker and in greater numbers; but, then, if we would but have patience, they would all come away spontaneously. While they maintain their hold, no medicine that we know of possesses the power of causing their expulsion; nor have we any drug that will destroy them without proving equally destructive to the parts to which they cling.
The LONG ROUND WHITE WORM (lumbricus teres, as it is technically called,) in form resembles the common earth-worm. They inhabit the small in testines; at least, are but rarely found in the large; and never, we believe, in the stomach. Farriers and grooms entertain strange notions about these worms; whenever they discover one, they never fail to ascribe the most pernicious effects to it: there appears, however, but little reason to believe that their complaints are well founded; indeed, from all that we have been able to collect, we should say that their destructive tendency has been greatly over-rated. The only unerring test of their ex istence is, that one or more have been discovered in the excrement; in which case a dram of tartar emetic may be given in bran-mash every night for a week; and after that, a brisk purge.
The THREAD-WORM (ascaris) much resembles the worm of the same name found in the human bow els. In the horse, they are found occasionally in prodigious numbers in the large guts, and above all, within the blind pouch of the ccecum. We believe this to be the most destructive species of worm; and one which it is advisable to get rid of. We have no sure evidence of their existence but their presence in the dung. Castor oil has been recommended for their expulsion: we do not reckon it to be so efficacious as aloetic purges, which, in these cases, should be preceded by five or six tur pentine drinks: each drink being composed of six ounces of spirits of turpentine, and a pint and a half of warm water, to be given twice a-day.
The TArn-wortm is exceeding rare in horses: our experience, which has been neither short nor limit ed, does not furnish more than three cases of it. Indeed, as a deceased veterinary author has truly observed, " but from the circumstance of the possi of it being met with, the tape-worm is so very rarely seen that it would scarcely deserve to be noticed as an enemy to the horse."