Cattle tick fever
Tick fever is the common name given to infection with either Babesiosis or Anaplasmosis parasites that are transmitted by the cattle tick and destroy red blood cells.
The ‘red water’ (red discolouration of urine) form of tick fever is caused by Babesia bigemina or Babesia bovis. Tick fever caused by Anaplasma marginale is unlikely to cause red discolouration of the urine, but better known for yellow discolouration (jaundice) of mucous membranes and the whites of the eyes.
Infection of cattle with Anaplasma or Babesiosis in tick free areas is notifiable.
Conditions where cattle tick fever is likely to occur
- Cattle tick (Rhipicephalus australis) are present.
Identification and diagnosis
Clinical signs that would lead a producer to suspect cattle tick fever include the following:
- presence of cattle tick is an indicator
- when cattle are heavily infested, ticks can be found anywhere on the body. On a lightly infected animal the main places to look are the escutcheon, tail butt, belly, shoulder, dewlap and ears
- cattle with tick fever initially have pale mucous membranes
- if the causal agent is Babesia, the disease can progress to the ‘red water’ stage, where urine is stained red by haemoglobin from broken down red blood cells
- if the causal agent is Anaplasma, cattle can become jaundiced (yellowish mucous membranes) and constipated
- tick fever is diagnosed by examining a stained thin blood film under a microscope.
An integrated approach to preventing cattle tick fever should consider the following:
- increasing Bos indicus content, as this is associated with higher resistance to tick attachment
- seeking genetics from tick resistant cattle. It has been estimated that selection of the right genetics could reduce the effect of ticks on live weight production by 60%
- using a combination of chemical treatments, and pasture spelling to control cattle ticks
- using the tick fever vaccine to prevent tick fever.