A new, rapid testing tool is being developed for sheep graziers in regions where Barbers Pole worm is a known or potential major risk to sheep health and productivity.
In development for several years by the Sheep CRC, the 'Haemonchus dipstick' is now in the final stages of field testing with a commercial partner.
Principal Veterinary Parasitologist with the Department of Agriculture & Food WA, Dr Brown Besier, CRC project manager, says the aim has been to develop a quick on-farm test as an alternative and substantial improvement to the traditional process of monitoring worm egg counts.
"It is aimed squarely at the Barbers Pole worm, which is a major problem in northern NSW and Queensland, and at times in southern higher rainfall zones, including Victoria and south-west WA," he said.
Dr Besier said the test dipstick was about 4mm wide by 10 cm long, and the total process from collection to result took up to half an hour.
"Farmers will still need to collect dung samples from the paddock, but from there it’s a much easier process," he said.
"The sample is mixed with water according to set dilution rates and the 'dipstick' is inserted into the solution, and the colours on the stick will change according to the amount of blood in the faecal sample."
The basis for the test is that Barbers Pole worms (Haemonchus contortus) are blood-sucking internal parasites, and as they feed in the abomasum, some blood passes through the digestive tract.
The dipstick is chemically sensitive to haemoglobin (a product of blood breakdown) and changes colour according to the amount of blood in the sample.
"The more worms that are present and active, the more blood in the faeces and a higher reading on the dipstick," Dr Besier said.
"It is a good indicator of Barbers Pole presence and activity, and therefore an indicator of the risk of deaths posed by Barbers Pole worms.
"Farmers and their advisors can then make a decision on if, or when, drenching is required."
The major benefits of the Haemonchus dipstick include:
• Speed and ease of diagnosis
• Easily accessible and able to be kept on-hand on-farm
• Reliable, accurate and inexpensive
Dr Besier suggests that usage will depend on the time of year – at peak times (especially summer) it could be used at least once/week to predict risks. Outside the main danger periods, its use depends more on recent climate conditions.
"Farmers rarely conduct conventional worm egg counts every week due to the cost, hence, industry runs a risk of stock losses when there are rapid increases in Barbers Pole infection," Dr Besier said.
"It is now over to the commercial operator to conduct the final stages of product development, which should be concluded in February to March 2009.
"We’re very hopeful that we will have a new tool to significantly lower the risks to animal health and productivity caused by this parasite."
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