Introduction

Caused by Leucocytozoon species, protozoan parasites of turkeys, ducks, guinea fowl, rarely chickens. The disease has a short course and morbidity and mortality are high. Simulid flies or culicoid midges are intermediate hosts. Survivors may carry infection. Different species of this parasite have been reported from North America, Asia and Africa.

Signs

• Sudden onset of depression.
• Anorexia.
• Thirst.
• Loss of equilibrium.
• Rapid breathing.
• Anaemia.

Post-mortem lesions

• Splenomegaly.
• Hepatomegaly.
• Anaemia.
• Microscopically - megaschizonts in brains of birds with nervous signs, schizonts in liver, gametes in erythrocytes.

Diagnosis

Lesions, histology and blood smears.

Treatment

None known.

Prevention

Separation from intermediate hosts, disposal of recovered birds.