We don't vaccinate with heptavac, not for any mistaken principles but because we have never had signs of clostridial diseases here. If they reared their ugly heads then of course we would vaccinate the whole flock. Heptavac isn't the kindest of injections, and back in the early days before we had the confidence not to vaccinate, our sheep frequently had painful abscesses at the injection site, in spite of using a fresh sterile needle on each sheep.
However, Dans if your ground has ever had sheep on in living memory, or you only have mesh fences between your fields and your neighbours, then vaccinate.
For the people you are buying from, take a careful look at their place and their animals, not just the sheep. Make your own judgement as to their knowledge and their animal health status. If you are happy with that, then buy the wethers. If not then go elsewhere. If you introduce disease onto clean land, then it can become a long term problem.
I would be slightly worried as to why the owner has had to worm and fluke 'several times', which could be a sign of dirty ground.
You are being sensible not to jump in with both feet when you are clearly not totally sure if these sheep are in prime condition. If you choose not to buy them, then there are millions of others to chose from - get the best
