Marianne is nicer than I am. I would remind the vet that Louis is MY dog and that the vet works for me, not the other way around. As such I would tell him I was stopping the Vetoryl, not lowering the dose, while Lou was on the antibiotics....and perhaps for a while after to see if he improved off the drug again. The vet is not the one who will have to deal with any adverse effects of his advice nor is he the one that will have to pay any extra vet bills that may occur as a result of his advice. But again, I'm not as nice as Marianne. LOL In reality I do understand that it generally seems in the UK vets seem to have much more control over pets that don't belong to them than vets in the US do and therefore are less willing to work with their clients.

Do let us know how your sweet boy is doing!
Hugs,
Leslie