This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
These are the larvae of the gad fly, Oestrus Equi. They are a great bugbear of the quack. Every case of colic or bowel trouble which does not yield to his treatment being attributed to bots. There is no doubt that they irritate the stomach and interfere with digestion when in large numbers. They often collect in such numbers around the piloric orifice (outlet of the stomach) as to almost obstruct that passage.
Treatment. - There are no known means by which they can be dislodged. A good dose of Barbadoes aloes might prove beneficial. When the aloes begin to operate an ounce of chloroform in half pint of water might be given.