POULTRY PARASITES 511 
year to another. If the parasites are known 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 grown 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. 
Fic. 214.—The gapeworm, Syngamus trachealis, of young chicks, attached to the inside of the 
trachea. A serious handicap to successful brooding when the soil becomesinfested. 
Intestinal Worms.—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 teaspoonful of 
castor oil. 
