PARASITES AND PARASITIC DISEASES OF HORSES 



19 



ment, and to withhold feed until after the carbon tetrachloride has 

 been given. A suitable purgative for foals consists of castor oil, 4 to 

 6 ounces, and neutral oil (mineral oil) 1 pint. This treatment has 

 not had critical test to determine its precise value. 



Prevention. — Prevention consists in special precautions with ref- 

 erence to stable sanitation, special care of foals, especially as regards 

 clean bedding which should be changed daily, if possible. Other 

 preventive measures are similar to those recommended in connection 

 with the discussion of ascarids and blood strongyles. 



THE LARGE STRONGYLES OR PALISADE WORMS 



The large strongyles are roundworms commonly known as blood 

 worms, red worms, sclerostomes, or palisade worms. They are red in 



Figure 12/ — Fortion of the tip of the cecum of a horse, showing blood strongyles 

 attached to the inner lining of the gut. The large worms are 8. equinus ; the small 

 ones are S. vulgaris. Natural size 



color and are commonly found firmly attached to the wall of the gut 

 (fig. 12) by means of a rather formidable mouth cup. Three species 

 of blood strongyles are of common occurrence in the colon and cecum 

 of horses, as follows : 



The large strongyle, Strongylus equinus (fig. 13, C), is from 

 about 1% to nearly 2 inches long by about one twenty-fifth to one- 

 twelfth of an inch wide; the mouth cup contains three teeth. The 

 toothless strongyle, Strongylus edentatus (fig. 13, A), contains no 

 teeth in its mouth cup ; otherwise it is similar in appearance to the 

 large strongyle, although it is somewhat smaller, females being about 

 iy 2 inches long. The single-toothed strongyle, Strongylus vulgaris 

 (fig. 13, B), is the smallest of the three species, and is from a little 



