Treat for fluke ... now!
16 May 2016
Recent tests have shown high levels of fluke infestation in beef and dairy herds in the Bega Valley. Tests were conducted by Local Land Services, in cooperation with Virbac, on five local beef farms. Tests on milk from local dairy farms have also been carried out by one of the local agricultural supply stores. Results highlight the need for action to be taken NOW to control liver fluke on affected farms.
South East Local Land Service District Veterinarian, Helen Schaefer said presence of liver fluke in your herd or flock can be confirmed by a faecal egg count, blood or milk test.
“Liver fluke is a parasite that causes liver disease in grazing ruminants including cattle, sheep and goats,” Ms Schaefer said.
“The parasite is of major economic concern to producers in high rainfall regions (>600 mm per year). Symptoms of liver fluke disease are not always obvious. Bottle jaw, abdominal pain, jaundice, anaemia and even deaths can be seen. Importantly, the major impact of disease often goes unrecognised. Losses include reduced weight gain, milk yield, milk quality and reduced fertility.
“The existence of liver fluke on a property requires the presence of the intermediate host, a small fresh water snail. Warm (>10ºC), wet conditions enable survival of fluke eggs and immature fluke, as well as the snail. A wet spring or summer such as we have seen in Bega over the last couple of years, increases the level of liver fluke infection in our herds and flocks,” Ms Schaefer said.
On farm, high risk areas for animals to pick up infection include places where the snail likes to live, such as shallow, slow moving water-ways, springs, dam over-flows, irrigation channels and creeks. Ideally, these areas should be fenced off. Irrigated pastures are also risky.
“Drenching is a vital tool to help control liver fluke,” Ms Schaefer said.
“Not all drenches kill all stages of liver fluke. Infection rate is highest in autumn, thus, the most important treatment is carried out in April to May. A drench effective against both immature and adult fluke, such as triclabendazole or a nitroxynil/chlorsulon combination (the latter only for beef) should be used.
“A second drench can be given in August to September. To help delay development of drench resistance, use a different drench to that used in April to May. This drench need only be effective against adult fluke. Such drenches contain clorsulon or oxyclozanide for cattle or closantel for sheep.
“A third drench is given in January to February where a high level fluke infection is known to exist. This drench must be active against both adult and immature fluke.
“Due to milk withholds, it is recommended to treat dairy cattle at dry off with a drench effective against immature and adult liver fluke (eg triclabendazole). For heavy infestations, treatment during lactation to kill the adult fluke may be needed. A drench containing clorsulon can be used as it does not have a milk withhold. The best time to do this is in August to September,” Ms Schaefer said.
Contact your district or local vet for further information.
Media contact: Helen Schaefer, District Veterinarian, 0417 296 739