This week I have come across a few “downer” sheep and also a few dead sheep that have died as a result of acute fluke. Fluke can have different effects depending on the stage and burden of the fluke.
Acute Fluke occurs as a result of large numbers of immature fluke burrowing through the liver of the sheep and can lead to sudden death. And secondly Chronic Fluke arises due to fluke sucking blood in the liver. Signs include loss of condition, anaemia paleness around the eye and swelling (bottle jaw) due to retained fluids. If not treated the animal will die.
There are products on the market that control immature and adult fluke and other products that only treat adult fluke. From now until January the greatest threat is from immature fluke and a product should be used that is effective against this form of fluke. Farmers are confused when ewes die from fluke even though they have been treated. This is due to using a product that only controls adult fluke and the problem is immature fluke. In other farm situations there is resistance to some products which make them ineffective. Consult your vet to draw up an effective control programme on your farm.
Aim of treatment
In the autumn aim to prevent immature fluke from developing following ingestion and prevent sudden death due to acute fluke. In the winter aim to kill adult and immature fluke and prevent liver damage and ill – thrift. In Spring/early summer aim to remove adult fluke and reduce summer infection of snails.
Fence off wet areas to reduce access to contaminated pasture. Get feedback on the level of contamination when slaughtering ewes/lambs. And get faecal counts done to establish the level of adult fluke contamination but remember this will not establish the level of immature fluke which cause sudden death.
I have had a number of calls this week about lambs dying suddenly. Clostridial is one of the fastest killers and is even difficult to treat even when got early. Vaccine failure and failure to administer the second vaccine or vaccine not being stored in the fridge were the main causes, although even when the correct steps around vaccine storage and administered correctly lambs can still die from it. Ideally the aim is to have the full course completed before a time of stress or housing or ad-lib feeding. This is not always possible and we just have to do what we can and vaccinate as soon as you can.