RABBIT IS SUDENLLY LETHARGIC HELP!!?

My usually active bunny has become very lethargic, she was fine this morning when i fed her, but when i went to check on her she was reclining and very lethargic.. We have syringed her some fluids and are going to do some mroe in a minute, but all the vets are closed and we dont know what else to do?? ANY HELP PLEASE!