Liver Fluke
There are 3 main diagnostic tests we use, however, no test is perfect. The tests are only able to give historic information on fluke infections. The 1st option is a faecal egg count. This test requires adult fluke to produce eggs in order to obtain a positive result, it will take 10-12 weeks after initial infection to become positive (i.e. a positive sample now would mean the sheep have had fluke for 10 weeks). The second option is faecal coprantigen, which also uses faeces but can detect fluke 2-3 weeks before the faecal egg count test. The third option is only suitable for lambs and uses blood to detect an immune response to the fluke infection. It can detect fluke from as little as 2 weeks post infection. If you get a positive result it is worth treating although it is important to remember that a negative sample may mean that we can’t detect the fluke rather than they’re not there!
Another possibility is to post mortem any dead sheep!