Who knew we had our own disease? Luckily it is a disease that we do not see too often anymore but the cause of it is still here and has the potential to affect livestock in our region.
What is ‘Tauranga Disease’? Well it is also know as ‘Bush Sickness’. Historically this was a wasting illness that affected sheep and cattle in the central North Island. Such was its severity that in the late 19th century, it was reported that it ‘stopped all progress and settlement” in our district. It was one of the most mystifying agricultural problems of the first part of the 20th century. Originally thought to be a form of iron deficiency it took more than 20 years for the exact cause, a lack of cobalt in the soil to be identified. This was the catalyst for the study of the links between soils and animal metabolism.
New Zealand scientists studied volcanic ash deposits (now called tephra) and found that bush sickness only occurred where tephras had been deposited during the Taupō and Kaharoa eruptions (about 200 AD and 1314 AD). Chemical analyses revealed that the sickness was caused by a deficiency in the trace element cobalt. Once identified it was readily cured by adding tiny amounts of cobalt to fertiliser. The success of the surveys and soil fertility experiments meant that abandoned farms could now become productive.
Cobalt (or Vitamin B12) deficiency is a disease that we still see in the Bay of Plenty today, we still have the same soils from those tephra, but due to our understanding of this link most of our farmland has been regularly fertilized with cobalt. However increasingly with more lifestyle and small blocks being grazed, and some forestry conversions, we have seen cases due to a lack of any cobalt being applied for many years. Symptoms of bush sickness are anorexia, illthrift, decreased milk production and anaemia which leads to death if not treated.
Luckily treatment and prevention is readily available, along with cobalt fertilization you can use oral or injectable doses of Vitamin B12, or treat with slow release bullets. Even quite severely affected animals will show a rapid response.
If you think that your stock might be deficient in Cobalt, we can perform a simple blood test to confirm, alternatively stock going to the works can have their liver levels checked. If you have any questions about ‘Tauranga Disease’, please contact any of our branches to discuss your needs with our vets.
Tony Austwick BVSC, BSc