Whenever you bring animals in, it is on a calculated pay-off basis. Gathering animals always stresses them. In the case of heptavac-ing or worming, the pay off is worth the stress, as it were. My sheep are not that used to being handled, but they will come in for heptavacing and worming, as the benifits of doing so far outweigh the disadvantage of causing them stress.
I don't get them in for much else other than worming, preventative treatment for flies, heptavacing and doing any limpers feet. If I can combine any of these, then all the better.