GREAT advice here - I'm so glad you found YT! WELCOME!
Another food to consider, if NB is tough for you to find is Wellness Simple Solutions - they have various flavors and are similar in concept to the NB allergy line. Unfortunately, BOTH brands contain flax (which makes me batty!), which some dogs cannot convert, and this then makes them...you guessed it...itchy
.
Also, I have changed from giving just fish oil to an oil that
also contains borage oil - which contains GLA. Fish oil is EPA and DHA, which is great - but GLA is essential if you think you're fighting atopy (vs. food allergy). The only oil I've found that meets what I need is Ark Naturals Royal Coat - you can get it online, but it is also available at Whole Foods and other health stores. This oil contains both fish oil and borage oil & Vit A/D/E. The body requires Vit E to process fish oils, btw.