42 DISEASES OF THE TRACHEA 



ANIMAL PARASITES IN THE TRACHEA AND BRONCHIAL 



TUBES. ' 



Syngamosis. Gapes in Chickens. 



Definition.— This is a condition due to the Syngamus 

 trachealis found most commonly in the trachea and bronchi 

 of birds. 



Etiology.— The only cause is the parasite Syngamus 

 trachealis, genus Syngamus. This is a small, round worm, 

 red in color, and the male is about 5 mm. long and the female 

 5 to 20 mm. A remarkable feature of these worms is per- 

 manent copulation, which is so intimate that the males 

 cannot be separated from the females without tearing their 

 integuments. This arrangement gives the worms a forked 

 or Y appearance. 



They attach themselves to the mucous membrane of the 

 trachea and larger bronchi and suck the blood. By so doing 

 they produce considerable irritation. The ova of the syn- 

 gamus are not laid but pass from the body of the female 

 which suffers rupture and usually occurs after death. 

 These ova are hatched in from one to six weeks according to 

 the temperature on damp ground or in water. The embryo 

 does not need an intermediate host in order to become trans- 

 formed into an adult worm. Birds ingest the embryos along 

 with food or water or the adult worm coughed up by an 

 affected bird may be swallowed; earth worms in infested 

 yards frequently have embryos in their intestinal tract and 

 when these are swallowed the embryos are liberated. They 

 then burrow out through the walls of the esophagus and 

 stomach and migrate through the tissues or possibly via the 

 blood stream until they reach the lungs and trachea. It has 

 been shown that fully developed parasites can be found in 

 the trachea twelve days after feeding the ova to healthy 

 birds. 



Symptoms.— This disease is seen most frequently in young 

 birds of from one to four weeks old, and is especially common 

 in chicks. They have a whistling cough, and the most 

 seriously affected open the beak at the same time stretching 



