GASTROPHILUS HAEMORRHOIDALIS 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 eases a great wasting of 
flesh in the horse. 
Perroncito (1902) describes lesions caused by Gastrophilus larve, 
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. 
Kroéning (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 larve 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 larve 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 larve. 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 when 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 larvee 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 larve 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 
