AFAIK Amoxicillin is best avoided as there are many other safer alternatives :?
I did once have a Rabbit who was given Co-amoxiclav (amoxicillin/clavulanic acid combo) by a previous Vet. The Rabbit had pneumonia. There were no adverse reactions to the abx and the Rabbit did recover. But I am not sure if that was more luck than anything else as the Vet was pretty lethal with Rabbits.