| Infections with
Haemoproteus
spp
are common in nondomestic birds. Pigeons and doves are frequently infected. Species are found in free-living ducks, quail, and turkeys but are rare to absent in commercial flocks probably because of very specific feeding habits of
Culicoides
spp
and hippoboscid flies, the invertebrate vectors. In free-living bird populations, females are more frequently infected than males. Until recently,
Haemoproteus
was considered relatively innocuous and of little clinical significance. Fatal infections can occur because of extensive widespread necrosis accompanying development of large exoerythrocytic megalomeronts in muscle, heart, liver, and lung. Mortality as high as 78% has occurred in bobwhite quail infected with
Isospora
lophortyx
. Similar meronts and lesions have been reported previously in cases of “aberrant leucocytozoonosis” and arthrocystosis. The diagnostic presence of large, pigmented gametocytes in mature RBC that often partially or completely encircle the nucleus without merogony can follow or occur simultaneously with systemic involvement. Sudden death without clinical signs or a prolonged course of weakness,
lameness, dyspnea, lethargy, poor growth, and anemia may be seen. Little is known about effective treatment, although antimalarial drugs may be tried. Chloroquine (5 mg/kg) and buparvaquone (2.5 mg/kg) have been reported to be effective in treating pigeons; diminazene and quinapyramine were either ineffective or toxic. Measures to control invertebrate hosts should help prevent heavy infections. |
