Dosing ewes today with triclabendazole for fluke. The stuff had been stored properly, shaken before use and was "in date". After struggling with two guns (good guns and clean too!) had to abandon the stuff and get a new batch. There must have been some small "lumps" in the drench that was causing problems with the valves on the guns. Is this a known problem with triclabendazole based drench? I know I`ve had the same problem before but can`t remember if it was the same product....frustrating...!