Every Japanese kitchen takes アレルギー (allergy) seriously. It's a useful word for you too, used the right way. Many chain restaurants have an allergen chart (アレルギー表). Ask for it: it usually shows egg, milk, and often beef, pork, chicken, fish and gelatine, dish by dish. On packs, the allergens follow the word アレルギー物質, sometimes as a chart of all 29. If you don't have an allergy, don't claim one: a kitchen may refuse to serve you rather than take a medical risk. The chart only lists allergens. Bonito, sardines and honey aren't on the lists, so dashi can hide behind a clean chart.