402 INTEKNAL PARASITES. 



circulation, and drain on the constitution by the presence of these 

 parasites in the intestines and blood-vessels, induce loss of con- 

 dition, general debility, unthriftiness of the coat, and sometimes 

 a dropsical swelling under the belly. The treatment appropriate 

 to the removal of these parasites from the intestines is similar 

 to that for round worms (p. 398), namely, by tartar emetic and 

 sulphate of iron, followed by a purgative, or we may try thymol 

 (p. 404). 



4. SCLEB.OSTOMA TETRACANTHUM {Strongylus tetracan- 

 thus) somewhat resembles the palisade worm in appearance. The 

 fore part of its cylindrical body tapers towards the head, which is 

 truncated (cut short off). The mouth is circular, and is provided 

 with four prominent spines (or suckers) ; hence its name. The 

 mouth has two other suckers (or papillae), but they are compara- 

 tively short. This worm uses its suckers to attach itself to the 

 mucous membrane of the intestine. It varies from a third to 

 three-quarters of an inch in length, and is white; although it 

 usually appears to be of a blood-red colour during life, by reason 

 of the blood which is generally contained in it. Hence, it is often 

 called " the red worm." 



This parasite and the palisade worm are found more or less 

 frequently all over the world. They are found in Australia, only 

 on pastures which have been for a long time under cultivation ; 

 lucerne paddocks give the greatest number of cases ; and these 

 parasites have apparently been imported into the Australian 

 colonies. The s. tetracanthus and s. armatus are almost always 

 associated together in their attacks on horses. 



Its favourite haunt is marshy land, like the Cambridgeshire; fens, 

 where it is a constant resident, according to Mr. H. C. Wilkie, 

 7.R.C.V.S. ("Journal of Comp. Path." March, 1896). Mr. W. 

 Shipley, jun., F.R.C.V.S., states: — "As far as my experience goes, 

 I believe certain pastures are infested with these worms, and colts 

 turned on them invariably get them. As a rule, they are low;- 

 lying, indifferent marshes. I have not, however, satisfied myself 

 as to their existence on some old heavily-wooded parks and 

 pastures, but I always look to old, poor marsh land. It is 

 certain that marshes on which husk is known to be prevalent are 

 also infested with these worms. I have clients who invariably 

 lose a colt or more from these worms, while their neighbours never 

 have a case " (The " Veterinarian," March, 1896). Husk is a form 

 of bronchitis which frequently attacks sheep, and which is caused 

 by the entrance into the windpipe of worms (strongyli) that are 

 closely related to the palisade worm and the " red worm." Jt 

 is therefore evident that ground which harbours the parasites of 



