Babesia bigemina (African)

Distribution:

Wide distribution in SA including large areas as in the Free State

Transmitted by

  • Boophilus decoloralus (Blue tick)
  • Rhipicephalus evertsi evertsia

(B. decoloratus tick (Blue tick) occurs in high numbers September to June)

larger parasite

Symptoms:

acute, red urine and death

Babesia bovis (Asiatic)

Distribution:

Eastern high rainfall areas – traditionally also in our area now

Transmitted by

Boophilus microplus (Pantropical Blue tick)

smaller parasite

Symptoms:

illness, brain symtoms, high fever, inappetance, depression & death

Diagnosis

of redwater is made on a blood smear on a microscope but differentiating the species requires blood samples to be tested by a laboratory; guessing can help when looking at the symptoms and also the geographical distribution of ticks but this is not scientific and no guarantee!

Vaccines

are frozen (dry ice/liquid Nitrogen) and injected intramuscularly as soon as the vaccine is thawed:

Immunity

develops after 4 – 6 weeks but is short-lived

Immunity

develops after 4 – 6 weeks and is long, even life-long cases

Animals need to be monitored for 5-21 days, post vaccination for reactions and then treated accordingly or all can be blocked at 5 days with either 1/3 dose of Berenil (or the full dose of Forray – not really recommended). Vaccines have a 7day meat withdrawal.

Vaccinating animals between 4-8 months of age leads to good immunity and few vaccine reactions are seen; animals should, however still be monitored.  Older animals can easily abort and even die post vaccinating depending on the level of supervision.

Outbreaks can be treated as follows:

1. Forray 65 / Imizol: 5 ml/100kg (better than 1ml/100kg (for anaplasma))
  • protects for 8 weeks
  • vaccination can only be done 4 months after Forray treatment
  • protects for 4 weeks
  • vaccination can only be done 2 months after Forray treatment
2. Berenil / Dizine / Dimisol:  7 ml/100kg
  • protects for 4 weeks
  • vaccinate 2 months after treatment
  • protects for 2 weeks
  • vaccinate 1 month after treatment

Endemic stability

means that calves born of cows with good immunity have passive immunity (via colostrum) for the first 6-8 months of their lives; if they get vaccinated or infected naturally by ticks in this period often lifelong immunity occurs.

Susceptible animals occur when:

  • Passive immune calves receive no booster infection or vaccination up to 8 months of age.
  • Animals are moved between clean and contaminated regions.
  • Total tick control is applied.
  • Animals, especially calves in dairies, are kept indoors ie. with no tick contact and then released onto pastures at a few months of age only.
  • Long periods of unusual weather cause an absence of contaminated ticks.

Weather ie. rainfall and temperatures determine the geographical distribution of tick population that transmit red water (see attached map).

Buying, selling and moving cattle also spreads the disease as tick populations hitch a ride from one farm or region to the next.

This is not a simple problem. Please contact your vet for further recommendations.