I'm going to throw my 2 cents worth here...
DISCLAIMER: RN, advanced training in microbiology & infection control
I'm cautiously optimistic that these changes in the FDA will lead to less discriminant antibiotic use. I do like the convenience of being able to buy almost any antibiotic & wormer I could want/need at my local farm store, I use them only as needed when there is a true medical need. I do my own fecal float tests & only worm when/if there are worms/eggs present & only treat for those seen. Antibiotics - they have a place & time for use. Just like in humans - bacterial infections sometimes need to be treated with antibiotics. Unfortunately with food animals (if you raise meat/dual source birds) you then have a choice to make: are you willing to eat a bird that has been treated with a short term episode of antibiotics or do you now have a new life-long pet. Also, you need to know which antibiotic to use for what. Great rule of thumb - don't hit with the heavy hitter when a lower level antibiotic will work for the pathogen. Use for a full course & don't miss doses, but don't do back to back runs or a shotgun approach. Have a general clue what you are treating.
In my personal flock, I do use antibiotics as needed, very discriminately. We do have an avian vet here but he is quite $$$$. I've consulted with him once to the tune of $300. It will be a rare case that I do that again. I'm lucky that I have the education & tools to diagnose a lot of things myself. I've used antibiotics only twice, for very limited episodes. I've wormed only once for confirmed worms in fecal floats.
I do think that the overall health practices of your flock have a major impact - as others have stated. I use high quality feed, fermented to provide good gut nutrition. I maintain good cleanliness in the coop/run; lots of fresh air; clean water (love my chicken fountain!) sunlight; darkness at night (also as important as sunlight); mental stimulation; and human interaction.
I'm a firm believer in vaccines in humans and pets. Spacing is important & I'm glad the pet vaccines are now multi-year. After seeing deaths from the Flu, we make sure to get our flu shot yearly. Herd immunity is important as not all of the population CAN get immunized. As far as my flock, we have a high mosquito area - so I do the pox vaccine as well a marreck vaccine.
Thanks for intelligent and civil adult conversation on this important topic. I will be picking up some antibiotics and other supplies before they are gone!
Edited by rnchick74 - 10/26/15 at 2:08pm