This study reports two clinical cases of avian haemosporidian infection caused by a Haemoproteus sp., involving a snowy owl (Bubo scandiacus) and a goshawk (Accipiter gentilis), at a zoo. The snowy owl died after presenting with anorexia, depression and lethargy. A blood smear with Wright's staining confirmed Haemoproteus infection. Necropsy of the snowy owl revealed hypertrophy of the internal organs, including the liver, gallbladder, kidney and adrenal glands. The goshawk showed anorexia, depression and a lowered head position, and was diagnosed with a Haemoproteus infection based on a blood smear. The goshawk was completely cured by treatment with a combination of atovaquone and proguanil hydrochloride. Both cases showed decreased erythrocytes, hemoglobin and hematocrit values on complete blood count.
Keywords: Accipiter gentilis; Bubo scandiacus; Haemoproteus infection; avian malaria; captive bird.