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