Background: The two main parasites include ectoparasites, which are those living on the external of the host (mosquitos, ticks) and endoparasites, which live internally in the host (worms). Nematodes or roundworms, cestodes or tapeworms and trematodes or flukes are the three categories in which endoparasites can be divided. Barbers Pole Worm is a nematode which attaches to and causes lesions to the fourth stomach or abomasum of sheep, and obtains nutrients through the blood. Large infestations of the parasite cause anaemia through loss of iron as well as protein, and are inevitably fatal ot treated or quarantined. Drenching, paddock rotation, selective breeding to improve immunity in offspring and the removing of the tail of the mob are some ways that can help to control this devastating parasite.
Symptoms of Barber’s Pole worm can be hard to distinguish, as signs can be caused by a number of parasites or diseases. A faecal egg count (FEC) is the only accurate way of determining a worm problem, but the Famacha method can show some indication by how pale the colour of the sheep’s eye socket or gums are. (refer to figure) Signs of infestation can include anaemia, lethargy, collapse, ailure to gain weight, breaks in the wool, bottle-jaw (sub- mandibular oedema), and in severe cases death. The control of barbers pole worm can be difficult, as females can produce between 5000 and 10 000 eggs a day, in which are carried out of the infected animal through faeces. If conditions are warm and humid, at 18 degrees C or above, the eggs then hatch as larvae and continue to shed skin to become an adult, while surviving on blades of grass for up to six weeks. (refer to figure) When grazing on pasture, sheep then consume the worms and the lifecycle of this parasite continues.
Barbers pole worm causes great loss of production in the sheep industry, especially in Queensland and northern New South Wales, where summer rainfall is common and conditions are ideal. Barbers pole worm is a parasite that thrives in warm climates between 25 and 35 degrees C. (refer to figure) Barbers pole worm FEC Introduction: A faecal egg count is conducted to find the quantitative amount of worm eggs per gram (epg). An FEC is usually carried out in a laboratory and is commonly used to find Barbers Pole worm eggs along with other nematodes, cestodes and trematodes.
Aim: To conduct a faecal egg count to estimate the number of Barbers Pole worm eggs passed through the faeces of several different sheep. Materials: – 2g faeces – 31. 7g salt 100ml distilled water – Beaker – Measuring cylinder – Microscope Stirring rod Whitlock McMaster slide and normal slide – – Plastic glove – Pipette Materials for recording data Method: 1. A faeces sample was taken from the ground and placed in a plastic glove. (noting the ear tag of the sheep if possible) 2. A saturated solution (NaCl) was made with 31. 7g of salt in 100ml of distilled water. g of faeces was added, stirred and then left to dissolve for approximately 20 minutes. 3. A pipette was used to take a sample of a couple of drops from the top of the mixture and placed onto the Whitlock McMaster slide as well as normal slide. 4. The slide was placed under the microscope, and was observed for eggs. 5. The quantitative amount of worm eggs per gram was calculated and recorded using: EPG =number of eggs in scanned area X volume of flotation solution(ml) + faeces sample(g) volume of faeces sample(g) X measurement volume(ml) Results Sheep group /coloured ear tag EPG Y4 3284 P438 R2 12936 G 63 Ram0 Discussion The quantitative amount of worm eggs found during the class experiment for R2 was equivalent to 8432eggs per gram (epg).
This result, when compared to the vet’s results at 12936epg, was found wanting. The report by veterinarian, Peter Lynch shows a quite varied result which was not unexpected due to better quality equipment and methods. R2 did not show visual symptoms of a barber’s pole worm problem, such as anaemia in the eyes or gums but according to the results, this sheep did have a high level of infestation, which needed to be treated romptly. The other sheep had results that were to be expected, with the ram- evident of immunity- at Oepg, the green tag at 63epg, the yellow tag at 438epg, and the purple with a slightly higher count at 3284epg.
The total averages of the sheep were calculated at a mean of 3344, a median of 438 and range at 12936epg. Good management practises and deworming strategies are essential for controlling parasites through the breaking of their lifecycle. Barbers pole worm infestations, as an endoparasite, can be treated in many ways including the use of drenches, addock rotation and selective breeding or ‘cutting the tail’ of the mob to improve genetic resistance in offspring. Each of these methods can be effective, but drenching is the most commonly used and successful way to control worm infestations. As the mob was evident of an infestation of Barber’s Pole worm, it was recommended by the vet that all sheep should be treated with some particular drenches or anthelmintics.
Drenches come in different categories or ‘families’ in which they can be broad or narrow spectrum and a single or multiple combination. Drenches can also be mixed, according to their properties and amilies to create a medication that treats a number of diseases or parasites in one application. Zolvix, Avomec Duel, Closal, Combat and Rametin were a number of anthelmintics that the vet recommended to use, in which should be used properly and in rotation to attempt to prevent drench resistance. This occurs when a strain of parasites survives the drench, even when administered at the correct dosage or concentration. Drenches should generally control at least 95% of the parasite population, but worms that are not affected pass genes on to offspring and create immunity.
Drench resistance in Barber’s Pole worm is common and a is large problem facing farmers and properties in Sothern Qld and Northern NSW, where the temperatures and humidity are ideal circumstances for this endoparasite. Conclusion and recommendations Overall, Barber’s Pole worm causes extensive damage to the Australia Sheep Industry through loss of production as well as funding for the treatment and prevention of this devastating parasite. Control opportunities include drenches or anthelmintics, paddock rotation, and improving genetic resistance in the sheep through cutting the tail or selective reeding.
As can be seen through the experiment, the school’s sheep did have a level of infestation in which is likely to be controlled mainly through the use of an anthelmintic. Selective breeding was also used to some extent, where the ram who was evident of immunity (0epg), would theoretically pass those traits onto offspring. Paddock rotation, while effective, is quite impractical in the school grounds due to lack of space and protection. Four paddocks would have to be fenced, and ‘dog- proofed if the sheep were to graze in each paddock for the duration of two weeks.