PLASMODIUM, HAEMOPROTEUS AND LEUCOCYTOZOON 



273 



similar to those of Plasmodium. These 

 break out of the oocysts into the body cav- 

 ity and pass to the salivary glands, where 

 they accumulate and are injected into a 

 new host when the fly bites it. 



Pathogenesis : U. columbae is only 

 slightly pathogenic. Infected birds usually 

 show no signs of disease. In relatively 

 heavy infections the birds may appear 

 restless and go off feed, and anemia may 

 result from destruction of erythrocytes, 

 but this is unusual. The liver and spleen 

 of affected birds may be enlarged and dark 

 with pigment. 



HAEMOPROTEUS SACHAROVI 

 NOVY AND MacNEAL, 1904 



Hosts : Domestic pigeon, mourning 

 dove (Zenaidiira macroura), turtle dove 

 {Streptopelia turtiir). This species is 

 primarily a parasite of wild doves which 

 may also infect pigeons. 



Location : Gametocytes in erythro- 

 cytes. Schizogony in endothelial cells of 

 blood vessels. 



Geographic Distribution : 

 America, Europe (Italy). 



North 



Prevalence : H. sacliarovi is common 

 in mourning doves. Levine and Kantor 

 (1959) tabulated 12 reports from this host 

 from coast to coast in the United States. 

 Among those studies in which relatively 

 large numbers of birds were examined, 

 Herman (1938) found it in 7% of 86 mourn- 

 ing doves on Cape Cod, Massachusetts, 

 Huff (1939) found it in 56% of 188 mourning 

 doves, mostly from Illinois, Coatney and 

 West (1940) found it in 67% of 18 mourning 

 doves in Nebraska, Couch (1952) found it 

 in 27% of 213 mourning doves in Texas, 

 Wood and Herman (1943) found it in 41% of 

 27 western mourning doves in Arizona and 

 California, and Hanson et al. (1957) found 

 it in 58% of 392 immature and 43% of 72 

 adult mourning doves in Illinois. In this 

 last study, its incidence was 31% in very 

 young doves and 52% to 69% in older birds. 

 Its incidence varied markedly in different 

 parts of the state and in different years. 



H. sacliarovi was found in 22% of 50 

 domestic pigeons in Nebraska by Coatney 

 and West (1940) and in 15% of 20 domestic 

 pigeons in Iowa by Becker, Hollander and 

 Pattillo (1956). 



Morphology : The macrogametes and 

 microgametocytes are found in the erythro- 

 cytes. They differ from those of most 

 species of Haemoproteus in that when ma- 

 ture they completely fill the host cell, en- 

 larging and distorting it, and often pushing 

 the host cell nucleus to the edge of the cell. 

 In addition, they contain very little pig- 

 ment. When stained with a Romanowsky 

 stain, the microgametocytes have pale blue 

 to almost colorless cytoplasm and a light 

 pink, diffuse nucleus, while the macroga- 

 metes have dark blue cytoplasm and a 

 dark pink to red, compact nucleus. 



The young gametocytes are ring-forms, 

 and all stages between these and mature 

 gametocytes can be found in the blood. 



Life Cycle : Huff (1932) transmitted 

 U. sacliarovi from the mourning dove to 

 the pigeon by means of the hippoboscid fly, 

 Pseiidolyncliia canariensis. However, the 

 natural vectors of this protozoon are still 

 unknown. In view of its high incidence in 

 mourning doves and the extreme rarity of 

 hippoboscid flies on these birds, the nat- 

 ural vector must be some other ectopara- 

 site, possibly Culicoides. 



Pathogenesis : H. sacliarovi is only 

 slightly if at all pathogenic in the mourning 

 dove. Becker, Hollander and Pattillo (1956) 

 considered that it caused the enlarged, pur- 

 plish livers which they encountered in 

 dressing domestic pigeon squabs from an 

 infected flock; there was apparently no 

 other evidence of disease. 



HAEMOPROTEUS NETTIONIS 

 (JOHNSTON AND CLELAND, 1909) 

 COATNEY, 1936 



Synonyms : Haemoproteus anatis, 

 Haemoproteus liermani. 



Hosts : Domestic duck, domestic 

 white Chinese goose, and over 23 species 



