Also known as Avian malaria
Leukocytozoonosis occurs in North America, Europe and Asia. It affects turkeys, chickens, ducks, geese, pheasants, ruffled grouse of all ages, however the young are most susceptible. Leucocytozoon is an intracellular protozoan transmitted via the bite of an invertebrate host, usually blackflies. L. simondi is found in ducks and geese, L. smithi is found in turkeys.
- Causes of Leukocytozoonosis >
- Effects of Leukocytozoonosis >
- Diagnosis of Leukocytozoonosis >
- Treatment & Control of Leukocytozoonosis >
Causes of Leukocytozoonosis
Leucocytozoonosis is also called avian malaria because it is transmitted by the bite of an insect.Turkeys, chickens, ducks, geese, pheasants, ruffled grouse. All birds can be affected, but young are most susceptible.
Leucocytozoon is an intracellular protozoan transmitted by the bite of invertebrate host. Its life cycle includes sporogony and schizogony (merogony) in the tissue cells and gametogony in erythrocytes or leukocytes of the insects. Elongated gametocytes with pale cytoplasmic horns exist in erythrocytes. Gamets are found only in leucocytes. Intracellular schizogonous forms are found in the liver. L. simondi is found in ducks and geese, and L. smithi is found in turkeys.
Mode of transmission
It is transmitted by blackfly bites. Sporozoites are in the salivary glands of the black fly. Wild birds and insects are a reservoir for infection.
Special note
It is immunosuppressive and common in turkeys on range in the southeastern United States.
Effects of Leukocytozoonosis
Signs include depression, somnolence, off feed, muscular incoordination, high mortality, anaemia, increased thirst, reduced mating and respiratory distress.
Vomiting, decreased egg production, egg weight and hatchability, and green diarrhoea may be seen.
Postmortem lesions
Haemorrhagic liver and enlargement of liver and spleen, congestion of the lungs, spleen and small intestine can occur. Fluid can occur in the body cavity, and the blood is thin and clotting retarded.
Diagnosis of Leukocytozoonosis
Laboratory blood and tissue smears are examined for the presence of parasite. Wright’s Giemsa Stain of red blood cells and lymphocytes show various life-cycle stages.
Treatment & Control of Leukocytozoonosis
Prevention
Control flies with Carbamate granules distributed by large scale aerial or treatment of grounds.
Eliminate carriers by spraying repellent within the houses to discourage entrance of flies. Clopidol fed continuously at 0.0125–0.0250% also reduce some infection.
Treatment
Clopidol, Phrimethamine (1 ppm) and sulfadimethoxine (10 ppm) are effective treatments.
