You can get amoxycillin (sp?) in a liquid form and flavored. I had to give it to my RB kitty Jamara once. They didn't have the tuna flavor on hand, the only thing they had was bubble gum (yes, bright pink). I had to get it in her as soon as possible, so I took it. She had no problem with bubble gum flavor until literally the last day. Jamara had enough and she spat it back out; all over the kitchen. I was finding little bright pink dots for a really long time!

Find a pharmacy that does special blending. I think the one near me is (maybe was, I haven't had to do this in a long time) Physician's Choice? Check with the vet, though, they'll know who does it. Let us know how it goes!