Yes, well here we have the great divide, Lorisa, between those who treat their hens as members of the family and take them to the vet if they are ill (except that they're not eligible for NHS care for free) and those who think of them more as productive pets or as commercial earners. The latter group cull their hens when they have obviously got beyond the stage of laying well, or have got some evidently incurable health problem. I would put myself in this group - when the time comes, mine get a quick and peaceful end. But all good poultrykeepers do worm their hens regularly with Flubenvet, because it makes such a difference to their ongoing health, and as you can easily obtain this online without a prescription, no vet is necessary.