BOT FLIES AND HORSES.

Tuapeka Times, Volume XXXIV, Issue 4835, 2 March 1901, Page 3

BOT FLIES AND HORSES.

The following letter has been received by the Agricultural Department, addressed to Mr J. A. Gilruth, Government Veterinarian, from Mr D. E? Salmon, United States Department of Agriculture :— " Replying to your, letter of the 19th November, I desire to fay that veterinarians in this country make no attempt to treat horses for b.ots, as jt \s not considered that they do the horse any injury. On the contrary, it is asserted by Borne that as a result of the little irritation produoed by their holding on to the mucous membrane of the stomach, that organ is stimulated, iiid digestion is promoted. la this country, about May and June, they are expelled with the excreta, and stablemen and others who notice them ia the manure will SOtaUtiime'B efolaia that tifc fcutfsa has

bots. ' Mr, of course, is nothing but the evolution of this parasite The mature bots, as they are passed from the horse at this period, penetrate a little beneath the soil, or under various objects, until their wings appear, when they are apt to crawl up on a blade of grass or straw, dry off, and fly away to lay more eggs, either on the lesrs of horses or they may deposit them in various plaoes, such as the margins of pools of water, so that when such water is drank by horses or the eggs ' are lioked from the forelegs, they hatch out in the stomach to form bots again, which normally remain in the stomach of the horse for about eight months of the year, and can be found in the stomach of any horse in this* country that is turned out to pasture during the summer and early fall, when the gad-flies are flying. This being the general impression in this country with regard to bots in the horse, your papers roust be in error in representing that a decoction of tansy is recommended by this department for the purpose of expelling them from the horse's stomach. Tansy has been used ; turpentine haß been used, and various anthemelmintios ; but I am not aware that any of them have any effects upon the bots, and do not believe that the bots are a serious detriment to the horse. Unless in very great numbers, they do not attach themselves to all the secreting half of the stomaoh, but show a preference for the cardia, which is lined by a raucous membrane like 'hat of the oasophagus. There is an impression which prevails among farmers, and, to an extent, among horsemen, in this country, that the presence of bots in the stomach of the horse is frequently the cause of colic, and sometimes the cause ot the rupture of that viscus. 'While they may at times cause colicy pains through the irritation produced by their little hooks and spikes, especially after they have entered the intestines, they certainly do not eat through the gastric wall, or cause perforation of the stomach, and when rupture of the stomach is revealed upon post-mortem examination of the animal that has had colic, it is undoubtedly been due to the over-disrention, most frequently as a result o' the accumulation of gas, even though bots are found in considerablenumbers in the stomach."