Redwater is a tick-borne disease listed with the World Organisation for Animal Health
It is often transferred between animals when farmers vaccinate multiple animals with the same needle.
However, calves must not be vaccinated before two months of age, because passive immunity transferred from the cow may negatively influence the vaccine. Infection of the unborn calf can occur, resulting in abortion or death of the calf shortly after birth.
Cattle infected with redwater will have red or brown urine (blood in the urine) and a high temperature of between 41°C and 42°C. (The norm is 37°C to 38°C.) The mucosa of the eye is pale. Infected animals will not eat, are listless, and their skin may have an unsmooth appearance.
Muscle tremors occur and animals react strongly to handling and noise.
Conditions are often more severe than other strains.
High fever, Parasitaemia (percentage of infected erythrocytes) – maximum parasitemia is often less than one percent.
Neurologic signs such as incoordination, teeth grinding, and mania. Some cattle may be found on the ground with the involuntary movements of the legs. When the nervous symptoms of cerebral babesiosis develop, the outcome is almost always fatal.
Animals are likely to separate from the herd, be weak, depressed, and reluctant to move
Haemoglobinuria and anemic dark-colored urine
Central nervous system (CNS) signs are uncommon
BB is predominantly observed in adult cattle. Infected animals develop life-long immunity against re-infection with the same species and some cross-protection is evident in B. bigemina-immune animals against subsequent B. bovis infections.
The survivors may be weak and in reduced condition, although they usually recover fully. Subacute infections, with less apparent clinical signs, are also seen.