Cattle and sheep farmers in the South West have been warned to look out for mud snails and any signs that their animals may have fallen prey to the parasites the snails carry.
At meetings across Dumfries & Galloway the risks of Liver Fluke and suggested control strategies have been discussed with experts from Scotland’s Rural College (SRUC). The project is funded by Scottish Government as part of its programme addressing climate change.
Heather Stevenson, a Vet with SRUC’s SAC Consulting in Dumfries, described how mud snails, living in boggy or wet areas, play an essential part of the life cycle of the liver fluke parasite. The eggs produced by adult flukes pass out in the animal’s dung, hatch into larvae and live inside the snails for a while before emerging to stick onto blades of grass where they form cysts, ready to be eaten by other livestock.
“The host snails like wet muddy areas, not just obviously wet rushy fields, but frequently in intensively managed grassland with poached, trampled areas such as those found near a water trough, or a field drainage ditch,” explained Heather Stevenson.
“Liver fluke disease affects cattle as well as sheep,” comments Dumfries based Michael Halliday, a consultant with the SAC Consulting Division of SRUC, who chaired the meetings. “It causes a loss of production, sickness and frequently death.”
Farmers at the fluke meetings discussed how the flat oval-shaped parasites, which can be between two and three centimetres long, shred the animal’s liver as they migrate, potentially in many hundreds, through it on their way to the bile ducts, where they settle and feed on blood.
Blood loss caused by this feeding, or liver failure caused by young fluke migration, leads to the common symptoms of liver fluke, such as anaemia, swelling under the chin (bottle-jaw) and poor body condition.
Those attending the meetings considered how farmers might manage stock to reduce the risk. For instance by grazing the most vulnerable animals, like lambs almost ready for slaughter, on low risk areas, such as reseeded fields with no wet patches.
Heather Stevenson also explained about the different medicines available for the treatment of fluke, and how, as the main categories are effective against fluke of different sizes, they are best used at different times of the year.
“There are basically just six different drugs which kill fluke, but these appear in a large variety of different forms, such as pour-on, injections and drenches. They also have many different brand names which can make it difficult to know exactly which drug you are using. The important thing is to check the product’s active ingredient and if in doubt ask your vet for advice” she said.
The key take home messages for farmers were to consider the risk of mud-snails being present in some or all fields and how this might impact on the stock grazed there at different times of the year. Take advice from the farm vet about testing the effectiveness of the various flukicides used on the farm, particularly triclabendazole . Finally consider carefully what size of fluke they are targeting at different times of the year so as to minimise reliance on one single treatment.
Other practical measures to help farmers improve efficiencies are considered at www.farmingforabetterclimate.org, you can find the initiative on Facebook or follow on Twitter @SACFarm4Climate.
