76 Veterinary Medicine. 



found in connection with the irritation caused by them. In and 

 near the pylorus inflammation and thickening of the mucosa has 

 blocked that opening and induced dangerous indigestion. 



Animals often show in winter a variable, capricious appetite, 

 emaciation in spite of the best feeding and care, unthrifty coat, 

 late in being shed, frequently recurring colics, a soft flabbiness of 

 the muscular system, a lack of energy, a tendency to swelling of 

 the legs and general ill health and this persists until the period 

 comes for the discharge of the bots, when a prompt recovery takes 

 place. This is especially true of horses that have been at pasture 

 the previous summer and autumn, while those kept indoors in 

 that season in the main escape. 



When detached in large numbers at a time the oestrus larvae 

 may actually block the pylorus or some portion of the small in- 

 testine and cause dangerous indigestions. This I have repeatedly 

 .seen in animals which have died of acute gastric indigestion. 



Again the larvse of CEstrus hsemorrhoidalis by hooking on to 

 the intestinal mucosa and especially that of the rectum and anus, 

 cause indigestions or severe itching and straining and according 

 to Hertwig eversion of the rectum. 



Symptoms. The symptoms caused by the presence of the 

 larvse of the oestrus in stomach or duodenum are varied and not 

 at all pathognomonic. Recurring colics, poor condition, swelling 

 of the legs, or under the abdomen, cough, contraction of the 

 masseter and turning up of the upper lip, occurring frequently in 

 the course of winter, spring or early summer, may create a more 

 or less well founded suspicion. The ordinary signs are well illus- 

 trated by the remarks of the late Joseph Gamgee : "I could not 

 rely on one of the Italian horses taken up from grass in the end of 

 summer, in less than nine months or a year, such condition I mean 

 as would fit them for any severe work." Of Italian horses 

 from the same breeders, but which had spent the previous .spring 

 and summer indoors, he says, " they invariably thrived so rapidly, 

 that in two months they were in beautiful condition as riding 

 horses. * * * They had lo,st the bots just before I obtained 

 them." The colics and indigestions resulting from the irrita- 

 tion of the pylorus or intestinal mucosa in their passage outward, 

 do not differ from ordinary attacks of the kind, but may often 

 be diagnosed by the presence of bots in the manure. 



