Bovine redwater, or Bovine babesiosis, is an often fatal tickborne disease in cattle. Bovine babesiosis is caused by a small protozoa in the red blood cells of an infected animal. This disease is spread by blue ticks, which are easily seen on the neck, dewlap, ears and belly of cattle. They are also occasionally found on the feet and tail.
Dr Heidi Kuhn, CCS veterinarian with the Gauteng Department of Agriculture, explains that two types of redwater – African redwater and Asiatic redwater – occur in South Africa. “The diseases are from the same family but tend to affect animals somewhat differently.
“With the exception of the more arid areas and high-lying parts of South Africa, African redwater occurs in most areas of the country. Asiatic redwater, on the other hand, is mostly restricted to the eastern parts where higher rainfall occurs.”
Know the signs
Farmers must be able to identify redwater in their cattle. “The starting point will always be a fever, which will rise to around 40 degrees a few days before the other clinical signs appear. Next, the cattle will become weak, tired and they will stop eating,” says Dr Kuhn.
“The colour of the mucous membranes is a very important indicator. Instead of being pink and healthy, it will have a pale pink to white colour. In very rare cases it can also have a slightly yellow colour. These signs may also be accompanied by diarrhoea.
A very common sign, especially in African redwater, is a red discolouration of the animals’ urine, which is where the name redwater originates from. This is only rarely seen in cases of Asiatic redwater.”
In severe cases of Asiatic redwater, the animal may show neurological signs. Dr Kuhn explains that animals will often lie on their sides, walk in circles or press their heads against objects. Sometimes the animal will simply act out of character and may be found dead a few hours later. Most animals are found dead without showing any symptoms.
Consult your veterinarian immediately if signs of redwater occur in your cattle. “Two main groups of medication are used to treat redwater: medication containing diminazene or medication containing imidocarb. The most important step is to read the package insert,” says Dr Kuhn.
She emphasises the importance of taking withdrawal periods into consideration. “This is the amount of time, after the medication was administered, during which the animal’s meat will not be suitable for human consumption.”
Vaccinate and protect
The most important step in preventing the disease is proper tick control. “There are two main means of preventing redwater through tick control. The first is where animals are dipped regularly. This is effective but may be costly. Cattle can also be treated with a long acting endectocide that will assist in the control of blue ticks over specific periods.
“The other method is known as endemic stability. Cattle can develop immunity to the disease by deliberately exposing them to the disease and ticks, especially when calves are young. Innate immunity only lasts for around six months. Exposing the calf to the ticks and the disease builds immunity in the animal.
“Immunity is maintained throughout their lives and dipping is only necessary when tick burdens become too heavy or cause damage. Farmers are therefore often advised to purchase cattle that were born in the same area in which they will be farming.
“A redwater vaccine is available and should be used with the appropriate discipline. It is best to consult with your veterinarian on proper vaccination protocol, especially to ensure that you will be able to monitor the animals after vaccination for the required amount of time,” says Dr Kuhn. – Marike Brits, Stockfarm
For more information, contact your MSD Animal Health representative or phone 011 923 9300. (ZA/ORUM/0218/0003e)
Thank you for the support of several role-players in creating this series: the Gauteng Department of Agriculture and Rural Development, Dr Gillian Declercq and the CCS veterinarians (Dr Lindsay Parvess and Dr Heidi Kuhn), MSD Animal Health, as well as Kenneth Ndlovu and the Amogelang team for their assistance and animals for demonstration.