BOTS AND WORMS. 381 



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

 species, but it is not necessarj' here to describe them. 



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

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

 they arc seen in the dung they are usually undergoing the natural i)rocx'ss 

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

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

 jihysie may jicrhaps liastcn the loosening of their hold: but we cannot 

 make them quit their tenement nmch before nature disposes ihem 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 ]>rechsposing agents. 

 Young animals are more subject to them than aged, and 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, najuely, first 

 the Ascaris meijahjccphala, or long round worm, wliich 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 i^resence 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 dry 

 brownish, matter adhering around the anus. AVorms 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 eilstence. 



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

 — ])ossibly not on account of the worms, but perhaps the worms find a 

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

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

 skin. 



783. TreatnuuL 



I'reviuus to the administration of medicine the horse should be kept 

 without food for at least twelve hour^^. A dose of two ounces of turj'en- 

 tine given in a pint of linseed oil, with half an oiuicc of tincture of opium 



