not sure how big or how sick your tortoise is , but I've once had two hatchlings in the 30 gram range that were very sick . not eating , lethargic , dull not completely open eyes , weak , distressed open mouth breathing , and nasal mucus , I assumed a bacterial infection/pneumonia , they were obviously , at least from my experience , going to die , and most likely soon ........ I was of the opinion nothing could be done , I had nothing to lose , and they would have been hard to replace , so i took them to a exotic animal/reptile vet , I told him I doubted he could dose them , he told me they were behemoths in comparison to some he had treated ..... he treated them with injectable fortaz and subq fluids ......... I think if your vet is not capable of dosing them , at minimum he could give you subq fluids , from what I've seen subq fluids by themselves will buy an animal more time to get well , and often makes them feel well enough to start eating again ..... i think thoughts on what vets can and can't do is very much a perspective based opinion .... it is possible i just got lucky , but the vet didn't appear to me to think it was luck ......jme