Oh I'm sorry but I had to giggle about sounding like an Easter basket.
It happens all the time with my cat, and I get her fluids done at the vets office!
But it doesn't seem to bother her, and they must have been more careful the other day after I mentioned it to them, because she wasn't crinkling last night.
I have to talk to them about the amount she's getting, it may be too much for a 7 lb cat. I notice the night she gets it done, before she has absorbed it all - it throws her balance off since the fluid seems to settle in her leg. And then the next day she sounds like an Easter basket. Bizarre, for sure.