The development and pathogenesis of Leucocytozoon simondi in Canada and domestic geese in Algonquin Park, Ontario

• Published in: Canadian Journal of Zoology
• Main Authors: Desser, Sherwin S., Ryckman, Andrée K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1976
• Subjects: Canada; Branta canadensis
• Online Access: http://dx.doi.org/10.1139/z76-075; http://www.nrcresearchpress.com/doi/pdf/10.1139/z76-075

The development of Leucocytozoon simondi was studied in naturally and experimentally infected Branta canadensis maxima, Branta canadensis interior, and Anser domesticus. The number of mature round gametocytes in the peripheral blood of the Canada geese increased between days 9 and 15 post exposure (PE) and decreased rapidly thereafter. Mean peak parasitemias recorded on day 13 PE were (per 1000 red blood cells (RBC)): 8 gametocytes in B.c. maxima, 16 gametocytes in B.c. interior, and 17 gametocytes in A. domesticus. About 3 weeks PE, gametocytes disappeared from the peripheral circulation and were not observed again during the autumn, winter, and spring in birds kept in the laboratory.Haematocrit determinations in the Canada geese revealed a low fluctuating anemia during the primary infection which subsided by day 21 PE. A more severe anemia was recorded in A. domesticus with a mean low packed RBC value of about 18% on day 11 PE. Immature and mature hepatic schizonts were observed in the Canada and domestic geese between days 3 and 8 PE. Neither megaloschizonts nor elongate gametocytes were seen. Clinical signs, pathology, and mortality commonly associated with L. simondi infection in ducks were not observed. Hypotheses are advanced to explain reports of severe pathogenesis associated with L. simondi infections in Canada geese in other localities.