Tick fever of Cattle

Tick fever, caused by Babesia bigemina, B. bovis, or Anaplasma marginale, is a potentially fatal disease principally affecting cattle in northern regions of Australia. The disease is spread by cattle ticks (Boophilus microplus), and causes a haemolytic anaemia, fever, and weakness.

Tick fever should be suspected in animals showing haemoglobinuria, elevated temperature, jaundice and anaemia. Babesia bovis (argentina) infections often cause nervous symptoms, followed by coma and death. Splenomegaly at necropsy is characteristic. The animal and its herd mates should be examined for ticks

Diagnosis and tests available

Diagnosis

Diagnosis is supported by history, clinical signs, pathology and supportive tests

Test

Sample(s) required

Days of the week test is conducted

Turnaround time1

Smear Examination

EDTA blood (purple top tube)

Monday – Friday

1 - 2 days

1 Turnaround times are provided as a guide only. For specific information about your submission please contact Customer Service.

Specimen requirements

Blood (with anti-coagulant)

  • 10 ml of blood collected into an EDTA tube
    • Submit chilled

Blood smear (unstained)

  • Blood smear (unstained)
    • Submit both thin (conventionally prepared smears), and thick blood smears
    • Ensure smears are clearly labelled with the animal ID and that it is a "thin" or "thick" smear
    • Submit in a plastic slide transport container to prevent breakage during transit
    • Protect slides from flies and excessive heat
    • Package blood smears separately from samples of formalin-fixed tissue, as formalin fumes will affect cell morphology

Blood smear preparation

  • Thin smears
    • Materials; two glass slide, EDTA blood, haematocrit tube or small gauge needle
    • Place the first glass slide on a flat surface, and put a small drop of blood at the base of the slide
    • Holding the second (spreader) slide at an angle of around 30o, bring the edge back to meet the drop of blood
    • Let the blood spread out along the edge of the spreader slide, then push it forward gently
  • Thick smears
    • Materials; one glass slide, EDTA blood, haematocrit tube or small gauge needle
    • Place the first glass slide on a flat surface and apply a large circle of blood
    • Tilt the slide forward, allowing the blood to spread out along the slide

Further information