I'm just off the phone with an online farm supplies place. I used to order online, but can't any more because everything is now on prescription and has to be done over the phone with a qualified person.
Me: "I'm looking for a white sheep wormer please, to treat nematodirus"
Assistant: "Certainly sir, we'd recommend XXXX. The active ingredient in that is Ivermectin"
Me: "Hang on, that's a group 3 clear wormer - I'm looking for a group 1 white wormer because it's only for nematodirus?"
Assistant: "No, that one isn't actually clear. I think it's more of a yellowy colour? It will treat lungworm and nasal bots as well though"
Me: "....................................."
OK, I should have been clearer and asked for a group 1 wormer right from the outset, but still, what on earth!?!
BTW, if this post makes absolutely no sense, there is a fairly
straightforward guide to the different wormer groups on the SCOPS website.