I don't know if I can give you much help, but Maggie did the same thing when she was teething. The best thing I can tell you is it only lasted a few days, then we were right back to normal. I remember one day she only drank 8oz of formula all day. She also did well with solids while teething, but the formula was difficult. I would try to get as much in her anytime of day she will take it. I offered the bottle every 30 minutes - 1 hour to try to get Maggie to take more. I hope it is just a phase for you. If she does seem to get dehydrated call your doc!! Good luck!!
We noticed Nathan's first tooth tonight. He is playing with bottles but still taking a good amount. I hope we do better with him!