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The worms which invade the horse most commonly, are the ascaris 

 megalocephala, or the large-headed lumbricoid worm, and the little oxyuris 

 curvula or maw worm. The male of the lumbricoid worm is rarely over 

 seven inches, but the female may attain a length of sixteen to eighteen 

 inches. This worm has a smooth body with transverse rings, and it may 

 occur in any part of the intestinal canal, although it is especially found in the 

 small intestines. The horse is known to be invaded by these parasites by 

 their occasional passage out of the body with the excrement. 



It is noteworthy that the eggs of the lumbricoids effectually resist dryness, 

 and it is possible that horses become infected with this parasite, by drinking 

 out of ponds containing sewage matter. In cases of invasion by this parasite, 

 the horse should have a full and nutritious diet. In the first instance, it is well 

 to give a ball containing six drachms of aloes and one drachm of tartar 

 emetic. Two or three days afterwards, a ball consisting of santonine thirty 

 grains, of sulphate of iron one drachm, of carbolic acid fifteen drops, of aloes 

 one drachm, made up with ginger and gentian and treacle to one ounce, may 

 be given twice daily for three or four days. 



The oxyuris curvula, or maw worm, is partly transparent, and is 

 marked with transverse stripes. In length, the males are one and three 

 quarters of an inch, and the females from three to four inches or more. This 

 worm has a long tail. Its usual habitat is in the large sacculated bowel, 

 where it may set up much local irritation. 



The horse rarely requires treatment for the expulsion of this worm. A 

 full dose of aloes may be administered, and clysters given once daily for a 

 few days will prove beneficial. Each clyster may be made of two ounces of 

 the oil of turpentine, with mucilage of starch one pint. 



We will now turn our attention to two other kinds of worms which 

 not infrequently infest the horse. One is called the four-spined strongyle 

 (Strongylus Tetracanthus), the other the armed strongyle (Sti'oiigylus 

 Armatiis). 



The four-spined strongyle is sometimes found in large numbers in the 

 horse, ass, and mule, and, though not uncommon in this countr)^, is not so 

 frequently met with on the continent. The males and females are of about 

 equal size, and occupy the walls of the large intestines of their hosts. They 

 set up by their presence localised congestion and inflammation, and the 

 formation of matter in the wall of the gut. The species is recognised by its 

 bright red colour, by the four conical spines surrounding the mouth, by two 

 neck bristles, and by the three-lobed long head of the male. The head, 

 when viewed in profile, is truncated, and seen from above it appears round. 

 The body is smooth, and presents indistinct rings. The eggs of the worm 

 probably gain access to the intestines of small insects, and the immature 

 form is swallowed by the horse in the water or in the food. The worms then 

 iDecome encapsuled in the lining membrane of the large gut. They are then 

 about 3'6 millimetres long when uncoiled. 



In this condition the worms cast their skins. They enter the cavity 

 of the gut, and undergo another change of skin prior to acquiring the 



