While helping Mama J recover from her Bobcat fever, as part of the regimen I gave her sub-q fluids. We did about 100ml twice a day, as that was what was recommended by the vet at the time. However, about 2 weeks after her vet visit she developed what I thought was a “kitty cold”. She sneezed/coughed, had watery eyes, and since a couple of other kitties also sneezed occasionally, I thought maybe she’d just brought back a virus from the vet office.
Then, one evening, I realized she still had a big pouch of fluid under her front leg. I decided not to give her fluids that night and in the morning, it seemed her “cold” had improved. Since by then we were pretty religious with the syringe feeding schedule (canned food mixed with water) AND I’d seen her jumping down to drink from the water bowl, I wondered if she might be getting too hydrated. Turns out I was right.
Here’s a great resource from a Chronic Renal Failure page.
In our case, we reduced fluids to just the evening and then eventually tapered them off all together within a few days since she was drinking on her own. Shortly thereafter, she started to eat and all was well.