Cowdriosis

Heartwater

• Severe disease of ruminants in sub-Saharan Africa caused by Cowdria ruminantium
• Vectors include Amblyomma ticks
• Carrier status can occur for up to 8 months in adult cattle and wildebeest
• Clinical disease in calves and lambs

• Clinical signs
  • Incubation period 4 weeks
  • Acute fever
  • Neurological signs including chewing, twitching of eyelids, circling, high-stepping gait, convulsions and recumbency; can be fatal
  • Subacute cases suffer from hydropericardium, hydrothorax and pulmonary oedema and congestion; splenomegaly and haemorrhages may occur

• Diagnosis
  • Clinical and post mortem findings in endemic areas suggestive
  • Orgnisms present in nuclei of endothelial cells in Giemsa-stained brain tissue
  • PCR, indirect immunofluorescence, ELISA and western blot

• Treatment and control
  • Tetracyclines during early disease
  • Immunisation using infected blood