Hi John, thanks for your question.
The airline rules are always changing. So what may have been true four years ago is no longer the case, at least not for certain air carriers. For example, the first time I flew overseas with my pet I needed a health certificate (for Delta airlines), which was quite costly. A few months later, Delta no longer required one. But other airlines still did.
This is why you always want to call the airline to confirm the requirements stated online. Also, be sure you aren't being quoted "UK" rules for the Republic. I've found that some airline reps don't know the difference.
Hope that helps,
Stephanie