EOTS. 321 



of no remedial agents being snccessfully employed, is nevertlieloss of 

 much importance to distinguish from other diseases of the alimentary 

 canal which its symptoms often resemble, viz. rupture of the stomach. 

 It may arise from a variety of causes, such as blows, falls, or a.ny violent 

 exertion, especially when the stomach is full of food. Corrosive poisons 

 and large numbers of bots have also produced it. But we most com- 

 monly meet mth it amongst aged horses as a result of the frequent 

 engorged state of the stomach. It is not uncommon amongst cab horses, 

 v/hen kept out many hours mtliout the nose-bag, and allowed a large 

 quantity of food when brought home. The rupture is generally situated 

 on the right side of the stomach, along its greater curvature. The symp- 

 toms of ruptured stomach somewhat resemble those of colic. The animal 

 will give evidence of severe pain, by great restlessness, pawing with his 

 feet, lying down and at times raising himself on his haunches, at others 

 resting on his breast. The countenance is distressed but anxious, the 

 body bedewed -with perspiration, pulse very quick and feeble, breathing 

 much accelerated. The animal will also make efforts to vomit, and in 

 some instances this has taken place shortly before death ; the vomited 

 material, passing through the nostril, is dischai-ged from the nose. These 

 symptoms will continue for a greater or less time, dependent upon the 

 extent of the rupture. If but a small opening exist, they may last 

 several days ; but if the opening be large, and a considerable quantity of 

 ingesta has escaped into the abdominal cavity, the sjonptoms will increase 

 rapidly in violence, and the animal frequently dies in convulsions in a few 

 liours. 



BOTS. 



Bots are a peculiar kind of grub, which at certain seasons are found in 

 considerable quantities adhering to the cuticular lining of the stomach of 

 the horse. The two varieties most generally met with are the oestrus 

 equi or large spotted horse bot, and the oestrus hemorrhoidalis or funda- 

 ment bot. Their history is curious, and we are indebted to Mr. Bracy 

 Clark for almost all we know of them. 



A species of gad-fly, e, the oestrus equi, is in the latter part of the sum- 

 nier exceedingly busy about the horse. It is observed to be darting with 

 great rapidity towards the knees and sides of the animal. The females are 

 depositing their eggs on the hair, and which adhere to it by means of a 

 glutinous fluid with which they are surrounded (a and b). In afewdaya 

 the eggs are ready to be hatched, and the slightest application of warmth 

 and moisture Avill liberate the little animals which they contain. The 

 horse in licking himself touches the egg, which adheres to the tongue, 

 and is conveyed with the food into the stomach. There it clings to°the 

 cuticular portion of the stomach, c, by means of a hook on either side of 

 its mouth ; and its hold is so firm and so obstinate, that it must be broken 

 before it can^ be detached. It remains there feeding on the mucus of the 

 stomach during the whole of the winter, and until the end of the ensuing 

 spring ; when, having attained a considerable size, d, and being destined 

 to undergo a certain transformation, it disengages itself from the cuticular 

 coat, is carried into the villous portion of the stomach with the food, 

 passes out of it with the chyme, and is evacuated with the dung. 



The larva or maggot seeks shelter in the ground, and buries itself there ; 

 it contracts in size, and becomes a chrysalis or grub, in which state it lies 

 inactive for a few weeks, and then bursting from its confinement, assumes 

 the form of a fly. The female, becoming impregnated, quickly deposits 

 her eggs on those parts of the horse which he is most accustomed to lick, 

 and thus the species is perpetuated. 



