Gastric and Intestinal Bots. 75 



Circumstantial accounts are given of the actual perforation of 

 the gastric walls by bots. Coleman relates a case in which they 

 had not only perforated the stomach but also the diaphragm and 

 were found in the pleural cavity. Roll vouches for cases of actual 

 perforation seen at Vienna, but allows that the 'walls of the 

 stomach were probably the seat of preexisting disease. Numan 

 found four or five holes in the duodenum, with oestrus haemorr- 

 hoidalis in the immediate vicinity and one actually engaged in a 

 hole. In a foal he found a great thickening of the mucosa on the 

 great curvature with, in its centre, six openings occupied by larvae. 

 Schliesse found in a paralytic horse a dozen larvae in a pouch 

 which connected the stomach through the omentum with the 

 vertebrae. Schortmann and Chiari found perforation of the 

 stomach by these larvae and a resulting peritonitis. Schlippe and 

 Delamotte have respectively found these larvae in abscesses of the 

 stomach. Hertwig attributes to them a fatal haemorrhage from 

 its gastric artery. While admitting the probability of such 

 lesions, there can be no doubt that a number of other alleged 

 instances of this kind have been examples of coincidence rather 

 than of cause and effect. Ulceration and perforation occur from 

 other causes and the larvae pass through. Abscesses open into 

 both stomach and peritoneum, allowing the passage of the larvae. 

 Pouches form from abscesses and other causes and are then oc- 

 cupied by the larvae. The gastric walls are digested while in a 

 state of paralysis or after death, and the larvae escape. Even 

 ruptures of the stomach from over-distension, strange as it may 

 seem, have in the author's experience been described as cases of 

 perforation by the larvae. In examining alleged cases this must 

 be kept in mind that perforations by the larvae must appear as 

 small round holes and in no case as an extended opening or 

 laceration. There must also be extensive peritonitis and espe- 

 cially around the points to which the larvae have hooked them- 

 selves. 



But independently of perforations the buccal hooks and the 

 spines of the larvae will sometimes irritate to the extent of causing 

 congestion, indigestion, inflammation, suppuration or even 

 haemorrhage which may prove dangerous or fatal. This is above 

 all the case when the bots are attached " to the right sac of the 

 stomach or the duodenum. In the left sac papilloma is frequently 



