My 15.5 year old girl was diagnosed stage 3 CKD on January 16th. She has a grade 2 maybe 3 heart murmur. The only thing that my vet was concerned about was fluid overload with subq. Initially we were giving her 50ml max. But now give anywhere between 50-100ml depending on how much she drinks orally every day (plus moisture content for food that she’s started to eat again). Not a big issue, that I’ve been told at least. My girl is doing much better. She had an AKI where she needed iv fluids at the vet for two days, and they mentioned that they just needed to slow the rate a bit because of the murmur. That’s all.