GASTROPHILUS HAEMORRIIOIDALIS AND OTHER BOTS. 7 



Warburton (1899) says: 



The irritation they set up can not fail, however", to be detrimental to the 

 horse's health even where no ill effects are obvious. The fact seems to be that 

 a horse in good condition and well fed can endure the presence of numerous 

 bots in the stomach without great inconvenience, but if the animal is in poor 

 condition gastric enteritis, perforation of the stomach, and death may result. 



In Miss Ormerod's report of 1890, Dr. Hy. Thompson, of Aspatria, 

 Cumberland, England, says : 



I have never seen the stomach entirely perforated, but the irritation induced 

 by the development of the larva causes in many cases a great wasting of 

 flesh in the horse. 



Perroncito (1902) describes lesions caused by Gastrophilus larvae, 

 some of which resulted in perforation of the stomach walls and death 

 of the animals. Cases of Flohill, Numan, Conti, and others, as well 

 as cases coming under his personal observation, are mentioned. 



Kroning (1906) reports having observed cachexia accompanied 

 with colic in young colts during the previous five years, and at- 

 tributes this to infestations of bots. 



Lahille (1911) makes mention of larvae causing death of animals 

 and cites the possibility of infection in the lesions. 



Velu (1913) reports that a drought greatly favored attacks in 

 Morocco and more than 1,000 larvae were usually found in post- 

 mortem examinations. All three of the more common species were 

 present, but G. nasalis caused lesions which resulted in death of the 

 animals. 



The universal distribution of G. equi and G. nasalis has familiar- 

 ized persons in every locality to some extent with bots of horses, yet 

 their opinions are naturally varied as to the economic importance of 

 the larvae. There are some who believe that there are no ill effects; 

 others think that they are beneficial ; while some even believe that a 

 horse will die if the bots are removed. Such conceptions are most 

 prevalent among "horse doctors" who are not in possession of an ef- 

 fective treatment for the removal of bots. On the other hand, it 

 is a difficult matter to convince a horse breeder that bots are bene- 

 ficial wdien his yearling colts kept in pastures have a rough coat, fail 

 to grow or fatten, show no symptoms of disease, and at the same 

 time possess a good appetite. Many breeders have made post-mortem 

 examinations of horses for their personal satisfaction. The finding 

 of hundreds of well developed larvae with conspicuous lesions con- 

 veys vivid impressions and greatly emphasizes the importance of 

 bots. Others, without a knowledge of the development of bots within 

 the horse, often make examinations after numbers have been passed 

 and the lesions healed ; or when the larvae are small and probably not 

 observed by an untrained eye they are regarded as less detrimental. 

 It is only by careful post-mortem examinations of large numbers of 



