182 DISEASES OF DOMESTICATED BIRDS 
and geese, performs the func- 
tions of a crop. The pres- 
ence of the parasites causes a 
distention of the gullet and a 
condition quite similar to dis- 
tention of the crop in fowls. 
The infested birds display ar- 
rested development, emacia- 
tion, difficult locomotion, epi- 
leptic movements, somnolence 
and lack of appetite. Death 
is frequently due to asphyxia 
resulting from over disten- 
tion of the gullet. 
At autopsy it is observed 
that the galleries formed by 
the worms appear as whitish 
curved lines which stand out 
in prominent relief against 
the congested mucosa. Mi- 
croscopic examination of the 
tissue will reveal the presence 
in the galleries of the worms 
and their eggs. 
Positive diagnosis is diffi- 
cult during life unless micro- 
scopic examination is made 
Fie. 23. Trichosoma contortum. A, caudal 
extremity of female; B, eggs from the of the feces or of water with 
uterus in various stages; C, caudal ex- 
tremity of the male. Enlarged 300 diam- Which the crop has been 
eters. (Railliet) rinsed. 
Treatment may consist of administering two tablespoonfuls of a 
mixture of turpentine with twice its volume of olive oil. 
Filaria cygni has been observed in the intestine and ceca of a 
swan which was exceedingly emaciated. 
TAPEWORMS 
General character. Tapeworms, also designated cestodes, con- 
stitute important parasites of the intestines of birds. When present 
in large numbers they occasion a disease designated teniasis. The 
individual worm is composed of a head called the scolex and a 
