306 Diseases of Poultry 



trouble is gapes the worms will be found attached in pairs to 

 the mucous membrane of the trachea. 



The two sexes are joined together in such a way that a pair 

 looks like a double headed worm. The female is about | 

 inch long and the male about \ inch. The worms are 

 pale in color when empty but when they have been feeding 

 they are red with the blood of the chick. The presence of the 

 worms in the trachea of a living chick may be demonstrated 

 by passing a gape worm extractor (a loop of horse hair or 

 fine wire or a feather with the vane removed except at the 

 tip) carefully down the trachea for some distance turning it 

 around to loosen the worms and drawing it out. If the 

 worms are present, some will be removed with the ex- 

 tractor. 



The presence of the worms causes an irritation and inflam- 

 mation of the membrane and stimulates the secretion of 

 mucus. Some of the accumulation of worms and mucus is 

 expelled by coughing. Sometimes part of it is swallowed 

 and expelled with the feces. The loosened material may be 

 drawn into the deeper air passages during inspiration. 

 Death may occur from suffocation due to the obstruction of 

 the air passages with worms and mucus, or weak individuals 

 may die from loss of blood. 



Etiology. — The only cause of the disease is the nematode 

 or thread worm Syngamus trachealis Siebold, called the gape 

 worm, red worm, or forked worm (see Figs. 65 to 67). 

 These parasites obtain their nourishment by sucking the 

 blood from the mucous membrane of the trachea. They are 

 attached in pairs to the membrane by their sucker-like 

 mouths. Besides bringing about a considerable loss of blood 

 the worms cause irritation and inflammation of the membrane 

 and a copious secretion of mucus. The two sexes are so 

 closely attached to each other that they cannot be separated 

 with tearing. The body of an adult female is swollen with 



