Treatment with an effective flukicide that controls all three stages of liver fluke remains the cornerstone of strategic control programs (Fasciola hepatica).

Elanco cattle brand manager, Kim Krilich, says liver fluke is a serious parasite of both sheep and cattle which can significantly impact performance and health.

“Liver fluke typically infests livestock in high rainfall and irrigated regions throughout southern Queensland, New, Victor and Tasmania, placing more than half of cattle and 15per cent of sheep in south-eastern Australia at risk,” she says. ¹

“Even in medium and low rainfall environments, infestations may be present in livestock introduced from endemic areas.”

Liver fluke has a complex life cycle that involves an intermediate host – a freshwater snail – and several free-living stages outside livestock.

“Wet conditions, swampy ground around permanent water or irrigation channels allow the survival of the fluke eggs, intermediate host and larval fluke,” Kim says.

“Livestock ingest most infective fluke cysts during late summer and autumn as they graze near wet marshy areas near creeks, springs and dams.

“Ingested cysts release immature flukes which penetrate through the intestinal wall and find their way to the liver, causing serious damage as they migrate through the liver tissue to the bile ducts."

"Fluke develop through early immature and late immature stages to adults over an 8-10 week period. In the bile ducts, adult fluke feed on blood, and shed thousands of eggs every day, continuing the lifecycle.

Cumulative and ongoing damage to the liver and bile duct and the associated inflammatory host response can significantly decrease growth rates and milk production, while blood loss can cause anaemia and ‘bottle jaw’.

Infected livers are condemned at abattoirs and in some cases, whole carcases can be condemned due to jaundice.

Liver damage also makes infested livestock susceptible to Black Disease, reinforcing the need for vaccination against Clostridium novyi (e.g. included in 5-in-1 clostridial vaccines).

“It is recommended to treat susceptible livestock in autumn with a flukicide that has activity against all three stages of liver fluke to eliminate new and established infections picked up during summer and early autumn, and minimise pasture contamination,” Kim says.

“An additional treatment in late winter or early spring using a different mode of action is recommended to control any late infestations or resistant strains, and further reduce any contamination before snail and fluke activity increases.

“A third treatment in mid-summer may be required in some instances, particularly if wet conditions persist throughout spring and summer.

“Likewise, all introduced livestock from fluke areas should be treated with an effective flukicide, particularly if their treatment status is unknown.”

Fluke faecal egg count testing, antibody blood tests and abattoir feedback can be used to help determine if treatment is necessary or the effectiveness of your current program.

Elanco markets a number of oral and injectable flukicides, including Fasinex 240, Exifluke 240, Fasimec Cattle and Bomectin F.

“Fasinex 240 and Exifluke 240 are oral formulations that contain triclabendazole,” Kim says.

“They are ideal for use during autumn or as part of a quarantine drench because they are effective against all three stages of triclabendazole-susceptible liver fluke.

“Fasinex 240 has the additional benefit of being registered for use in both sheep and cattle, making it suitable for use in mixed livestock enterprises.

“Fasimec Cattle is an oral formulation that combines triclabendazole and ivermectin for the additional control of gastrointestinal roundworms, lungworm and sucking lice in cattle.

Bomectin F is an injectable treatment for cattle that contains clorsulon and ivermectin.

“It is suitable as a late winter or early spring treatment to target adult fluke and as a rotation partner for triclabendazole-based treatments,” Kim says.

“It has a nil milk withholding period, making it suitable for use in lactating dairy cows.”

Always read and follow the label directions, and ensure good agricultural practices are followed for optimal parasite control.

Flukicides should be used together with pasture management and improved drainage to reduce the exposure of livestock to ‘flukey’ pastures. This includes fencing off wet, swampy areas to help break the lifecycle and minimise current and future exposure to infective cysts.

References: 1. Shephard, R. et al. (2022). Priority list of endemic diseases for the red meat industry – 2022 Update. Meat & Livestock Australia. Report B.AHE.0327