BOTS AND WORMS. 381 



often adhere by their tenacula to the fundament. There are several 

 species, but it is not necessary here to describe them. 



Their presence does not seem usually to act injuriously on the health 

 of the horse, though occasionally the stomach is eroded by them. When 

 they are seen in the dung they are usually undergoing the natural process 

 of being voided before their transformation ; and if we have patience, 

 nature will quietly expel them without our aid. At this period, a dose of 

 physic may perhaps hasten the loosening of their hold ; but we cannot 

 make them quit their tenement much before nature disposes them to do 

 so, inasmuch as their bodies are hard and insensible to the action of any 

 medicine, and their heads are enveloped in the lining of the stomach. 



782. Intestinal Worms. 



The cause of the production of these parasites in the body is enveloped 

 in mystery. Poverty of the system, pasturing in marshy or wet ground, 

 or the use of stagnant waters are undoubtedly predisposing agents. 

 Young animals are more subject to them than aged, arid weakly than 

 stronger subjects. They are however often found in horses to which none 

 of these conditions apply. 



Worms derive their nutriment by suction from the intestinal secretions. 

 They die, if the animal dies ; or if voided, they perish immediately. 



Two kinds of worms are commonly found in the horse, namely, first 

 the Ascaris megalocepliala, or long round worm, which we frequently dis- 

 cover in the dung. They inhabit the small intestines, and are sometimes 

 twelve inches long. Secondly, the Oxyuris curvula, a small needle-like 

 lively worm found in great numbers in the large intestines and rectum. 

 This worm is usually white in colour, and about half an inch long. 



In some cases the presence of Worms may be detected by their being 

 excreted along with the dung, whilst in other cases their presence can 

 only be suspected by a peculiar hard, dry, unthrifty appearance of the 

 coat, or at other times by frequent whisking of the tail and by some diy 

 brownish matter adhering around the anus. Worms may also exist for a 

 length of time without presenting any outward appearance which might 

 lead to their detection. 



In some cases they injuriously affect the health of the horse, whilst in 

 others they seem to do no harm. We are as little able to explain this 

 difference in effect, as to explain the cause of their existence. 



As a general rule, when a horse has worms, his system is out of order 

 possibly not on account of the worms, but perhaps the worms iind a 

 suitable tenement in his intestines, because they are out of order just as 

 the mange insect will lodge in an unhealthy in preference to a healthy 

 skin. 



783. Treatment. 



Previous to the administration of medicine the horse should be kept 

 without food for at least twelve hours. A dose of two ounces of turpen- 

 tine given in a pint of linseed oil, with hall' an ounce of tincture of opium 



