Do you have any pain meds (meloxicam)? I don’t like to give meds without the vet’s instruction, but if she’s had meloxicam before I would be more inclined to give that than metaclopramide, as giving metaclopramide without pain meds can be very painful for the bun as it can cause cramping and could make things worse for her. If you can reasonably get her to a rabbit savvy vet today I would if she hasn’t perked up in another hour or so (usually simethicone helps in the first couple hours if it’s going to help at all).
If getting to the vet today isn’t possible the best thing you can do for her is to provide supportive care until the vets open: you can offer hay or mint tea, syringe small amounts of water or hay tea, make sure she stays warm (take her temp and/or feel her ears), and give her tummy rubs. If she full stops eating I personally would syringe feed, with the caveat that this can be harmful if the bun is fully blocked or having true bloat, so whenever I have doubts I just give tiny bits of food.
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The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.