02 POULTRY DISEASES 



Syngamus Trachealis 



This parasite is sometimes called the Sclerostoma synganius, 

 and popularly the forked worm or gapeworm. There is an- 

 other worm slifrhtly larger than this one that infests the 

 bronchi and trachea of ducks, swans and geese. It is called the 

 Siingarn us hronchiaJis. 



Description. — The male is very much smaller than the female, 

 upon which it exists as a parasite. Fig. 41 illustrates these worms 

 in copulation as they are always found. A, illustrates a section of 

 mucous membrane. B, the male, which, it will be noted, is much 

 thinner than the female and scarcely one-fourth inch long: and C, 

 the female, about one inch in length. The mouth 

 parts are surrounded by a capsular arrangement by 

 which it holds firmly to the mucous membrane of the 

 trachea (windpipe) or bronchi. The mouth parts 

 are provided with chitinous teeth, with which they 

 wound the mucous membrane; from this wound they 

 suck blood. 



Life History. — The female produces eggs which es- 

 cape from her body only after she is expelled from 

 the host and her body decomposed. The embryos 

 thus escaping from the decomposing and disintegrat- 

 FiG. 41. Syn- ^^S female are taken up by earth worms. Thus, 

 GAMus Trache- chicks drinking contaminated water, or eating these 

 ALis (NATURAL infestcd earth worms, in turn become infested; or if 

 ^^^^^' the chick should pick up an expelled female contain- 



niembrane'^ "of ^^^§^ ^^^® mature eggs, the embryos would be liberated 

 trachea; in the stomach of the chick, in which case they mi- 

 H, male; C, grate to the air sacs and air passages and grow to 

 female. maturity. 



Ellers has produced the disease by feeding embryos 

 fresh from the trachea of infested birds. It would therefore appear 

 that an intermediate host is not required, but that a bird may be- 

 come infested by picking up an expelled worm or some of the 

 tracheal discharge containmg the embryos. 



Symptoms of Infestation. — "Wild as well as tame birds are 

 susceptible to gapeworm infestation (chickens, turkeys, pheas- 

 ants, partridges, pea-fowl, magpies, black storks, starlings, 

 crows, parrots, swifts, woodpeckers and martins all have been 

 reported as having become infested). 



The poultryman's trouble is usually with young chicks and 

 turkeys. The small, immature gapeworins or eggs containing 

 the embryos find th(Mr way to the intestinal tract of the young 

 bird as described above, and from the intestine they migrate 

 to the trachea (wind pipe) and its branches and attach them- 

 selves, where, by growing in size, they gradually o])struct the 

 passage of air to the lungs. As a result, the bii'd finds ])r(^ath- 

 ing difficult and after a while gasps for breath, extending 

 its head high into the air, finally becoming asphyxiated. T^su- 

 ally a liiinp may be found by feeling along the trachea, if 

 the worms be lodged in that part of the trachea, which is 



