INTERNAL PARASITES 205 
LEUCOCYTOZOON INFECTION IN DUCKS 
Wickware observed an outbreak of disease among young ducks 
under circumstances that led him to suspect that leucocytozoa were 
responsible. Bacteria could not be excluded as a cause, for it was 
not possible to seed culture media. 
Symptoms. The affection runs a rapid and fatal course, with 
few symptoms to indicate its onset. Impaired appetite is first no- 
ticed.in that the birds refuse to respond to the call for feeding. In 
some cases ducks succumb during the first paroxysm, while others 
survive a series of exacerbations. Affected ducks lie in a semi- 
comatose condition with the neck bent backwards and the head resting 
upon the dorsal portion of the spinal column. When roused from 
this stupor the bird experiences a period of intense excitement during 
which remarkable movements are made. The head is held in various 
positions, or describes circles in the air, or at other times swings to 
and fro. In some cases the neck is completely turned on itself with 
the head resting on the ground in an upright position. The power 
of equilibrium is lost and the bird turns over backwards until ex- 
hausted. In recovered birds, there is lameness and consequent 
difficulty of locomotion. Purulent ophthalmia with adherent lids 
is a quite constant symptom. The mortality is about 65 to 70 per 
cent. 
Etiology. The leucocytozodn present in the blood of ducks in 
two outbreaks of disease is designated by Wickware as Leucocytozoon 
anatis. ‘The shape of the parasites is fairly uniform although there 
appears to be considerable pleomorphism in the gamete forms. The 
predominant type is a spindle shaped organism 85 microns to 60 
microns in length by 10 microns in width, showing an oval elongated 
or irregularly shaped nucleus, with dark chromatic band extending 
along one border. With Giemsa, the nucleus stains.a dark blue and 
has a granular appearance. In the center there may be observed a 
small chromatin staining body varying slightly in’ shape. The 
cytoplasm appears almost transparent or at most stains a faint pink. 
At each end it terminates in an acute angle. Considerable varia- 
tion occurs in the staining characteristics of the mature forms. 
Morbid anatomy. Other than acute hemorrhagic inflammation 
of the large intestine behind the ceca, no abnormality of the visceral 
organs was observed. The blood in all cases of infection showed an 
increase of eosinophiles, besides the leucocytozoa. 
