PALISADE WORMS. 399 



months old would be 10 grains three times a day, and continued 

 for a week. 



Thymol is used for the relief of this disease (p. 404). 



2. THE THREAD OR MAW WORM {oxyuris curvula) is about 

 an inch and three-quarters in length, when of full size. Its tail 

 end is thin and whip-like; its front end being thicker and 

 terminating in a curve, somewhat in the form of the crook of a 

 stick. The presence of these parasites produces little disturbance 

 of the animal's general health; although it may cause irritation 

 about the dock, which will be made manifest by the horse rubbing 

 his tail. Accompanying these worms, a light yellow waxy sub- 

 stance (the eggs of the parasites) will be found adhering to the 

 skin immediately below the anus. Thread worms, like round 

 worms, frequently oome away with the dung. 



Treaiment.^To clear out the rectum, back rake (p 649), give 

 an enema (p. 643) of warm water, and then administer another 

 enema of six ounces of oil of turpentine in half a gallon of linseed 

 oil. If, after a repetition or two of this treatment, the worms are 

 still found in the horse, we may conclude that they are too far up 

 in the intestine to be reached by an enema, and we may conse- 

 quently treat the animal in the manner directed for round worms 

 (see preceding page). Anointing the inside of the anus with a 

 little mercurial ointment on the finger, will allay the itching and 

 will hasten the removal of those worms which have taken up their 

 abode near that part. 



3. THE PALISADE WORM (sclerostoma equinum, or strongylus 

 armatus) is a very common parasite in horses of most countries, 

 although its presence in the animal usually remeiins unsuspected. 

 The pastures on which it is found are generally poor and marshy. 

 Its body, which is grey or brownish-red in colour, is more or less 

 straight and stiff, and its front part is thicker than its hind 

 extremity. It varies a good deal in length ; the male, from f 

 inch to IJ inch, and the female, from eight-tenths of an inch to 

 2 inches. It is about twenty times as long as it is thick. It 

 occurs in the horse in two forms, namely, in an adult and in an 

 immature state (before it arrives at puberty). In the former, it 

 implants itself on the mucous membrane of the caecum and large 

 colon, by means of its armed mouth ; and in the latter, it resides 

 chiefly in aneurisms, and in cysts underneath the mucoUS mem- 

 brane of the caecum and large colon, but is occasionally foUnd in 

 other organs, such as the brain, testicles and liver. 



In the adult state, the large intestine is sometimes studded 

 with them. More than 1,000 were counted on a surface of two 



