Giardia sp. was found in the white stork (Ciconia ciconia) in The Netherlan
ds for the first time. The Giardia sp. trophozoites that were found in the
feces of a 6-wk-old white stork, were examined by light microscopy. The par
asites closely resembled Giardia ardeae that bad been isolated by others fr
om several species of wading birds belonging to the order Ciconiiformes, sh
aring a deeply notched adhesive disk, a single caudal flagellum, and a sing
le round median body. Serologically, the parasites did not react with anti-
Giardia intestinalis monoclonal antibodies. Although no signs of intestinal
disease were observed in the stork chick, the presence of parasites in all
stages of development and the huge number of parasites show that the stork
chick was experiencing an active infection with G. ardeae type parasites.