I have to give my bunny, Bindi, fluids once a day due to him not being able to drink well on his own. We do warm the fluids as cold fluids can be quite shocking to the system. We fill the sink with warm water and let the fluids sit in there for several minutes. It should be warm, we usually do lukewarm. Always check it first to make sure it’s not too hot or cold.
I don’t do the actual need part as I get queasy but my husband does that part and says it’s much easier with a bunny than the times we’ve had to give our cats fluids. Their skin is loose and easy to insert the needle. He does it right at the scruff of the neck. Lift the skin up, make a v and insert it at the tip f the v.
We give our bunny 60 ml a day for a poorly bunny in stasis, I’ve seen my vet give twice that amount. It probably depends on the size of the bunny. My little guy is less than 5 lbs.
It’s good that you are researching this because you are right, I have seen fluids turn around a very sick bunny. Sometimes it just gives them the little boost they need.