Ciao Sofia!
I'm so glad you're coming to Ireland with your furry friend!
When it comes to bring the dog on the bus, I confirm that only guide dogs and assistance dogs accompanying passengers are permitted to travel. Whereas, as stated in
this article, small dogs can be carried on trains free of charge provided they travel on the owners lap.
Also, I'd like to recommend that you read this thread about
travelling with dogs, and you may find other useful information about bringing your dog to Ireland on our
page. If you need further information, you can always reach out directly to the company you want to travel with, so that they can assist with planning carefully your trip.
If you have any other questions or tips to ask, please feel free to reply in Italian.
;)