POULTRY PARASITES 511 



year to another. If the parasites are knowTi to exist, the best 

 procedure is to plow the ground and lime it thoroughly. Do not 

 use it for young chicks for a year or two — not until some crop 

 has been gro^^^l upon it, and the ground worked over considerably. 

 When only a few chicks are affected, the worms can be extracted 

 with a horsehair loop or commercial extractor. 



Fig. 214. — The gapeworm, Syngamus frachealis, of young chicks, attached to the inside of the 

 trachea. A serious handicap to successful brooding when the soil becomes infested. 



Intestinal TT^om;.s. — Internal parasites are represented by two 

 distinct kinds of intestinal worms, known as roundworm and tape- 

 worm. The former are round, smooth worms (Fig. 215), tapering 

 at each end, pointed in front and blunt in the rear. They derive 

 their nourishment from the feed, and, if present in large numbers, 



Fia. 215. — The common roundworm, Heterakis perspicillum. When present in large 

 numbers they are a serious hindrance to production. 



greatly impair the nutrition of the bird, perhaps interfering with 

 digestion and causing obstruction. 



The best treatment is to give some drug which will cause them 

 to loosen their hold on the lining of the intestine, and to follow 

 this up with a laxative to expel them. For individual fowls one 

 teaspoonful of oil of turpentine may be given one hour before 

 feeding in the morning, and three hours later one teaspoo:aful of 

 castor oil. 



