Zonked out on antibiotics?

[herbi7]

Hi everyone, my lovely bouncy Willow has developed a large abcess near her bottom (at least that's what the vet thought it was, I took her in this morning) and she has been put on antibiotics. The thing that's worrying me is she has been fine with it up till now, zooming around and playing as usual, but about half an hour after her first dose of antibiotics (i gave it to her in some sweetened porridge and she had about half of it) she is really subdued and sleepy and just sitting on her top level in a little huddle with her eyes closed. She was happy enough to come out and play just after she had eaten and seemed bouncy as usual but now she really isn't herself. It's not normal for her not to be super-lively! Is this normal as a reaction to antibiotics or should i be worried?