56 PARASITES OF THE DOMESTIC ANIMALS 



than that toward the pyloris. Where they occupy the glandular right 

 half, especially if in large numbers, they interfere with the digestive 

 secretion and its proper contact with the gastric contents. In excep- 

 tional cases they may be sufficiently numerous about the pyloris to 

 form an obstruction to the passage of food material into the small intes- 

 tine; or even the duodenum itself may be invaded. Under these latter 

 conditions the larvae bring about nutritive disturbances and may cause 

 attacks of acute indigestion with its accompanying manifestations of 

 pain. When we consider, however, the large number of horses essentially 

 harboring the larvae of the horse botfly, as indicated by the widespread 

 prevalence of the insect, we must conclude that they are comparatively 

 inoffensive, for in most cases there is an entire absence of any apparent 

 disturbance and, with the exception of the voiding of the bots, nothing 

 during the life of the animal which would lead to suspicion of their 

 presence. 



Treatment. — The larv« of Gastrophilus are so resistant that treat- 

 ment having in view their destruction or expulsion has been generally 

 unsatisfactory. Such agents as preparations of tar, benzine and turpen- 

 tine, which are sometimes used for this purpose, add irritation to an 

 already irritated gastric mucosa and, for this reason, in connection with 

 their general ineffectiveness, the advisability of their use is questionable. 

 AVhere the presence of the bots in sufficient numbers to cause disturbance 

 to the health of the animal is suspected, gastric irritation may be allayed 

 to some extent by feeding mucilaginous materials, such as flaxseed meal. 

 Hay in such cases is best fed chopped, and a substantial nutritive diet 

 should be looked to as compensatory to the loss of nutriment. 



A treatment recommended by Peroncito and Bosso (1894) consists 

 in the administration of carbon bisulphide to adult horses in gelatin 

 capsules, each containing 8 to 12 grams (2 to 3 drams). After fasting for 

 twelve to twenty hours, the horse is given one capsule ; after one hour a 

 second capsule is given, and after another hour a third. As carbon 

 bisulphide is strongly irritant, care should be taken in the administration 

 of the capsules that the cap does not become detached and that they do 

 not become crushed in the mouth. 



In so far as clinical observation can determine the presence of bots, or 

 lead to the conclusion that a remedy has caused the expulsion of any 

 considerable number of them in proportion to the infestation, this treat- 

 ment is said to be generally satisfactory. It seems reasonable to con- 

 clude that an agent sufficiently active to cause the expulsion of these 

 robust larvae from their secure attachment would have a severely irritant 

 effect upon the gastric mucosa, though this membrane of the stomach 

 appears to have a greater tolerance for such assaults than that of other 

 regions of the alimentary tract. 



