Complications due to too much sub q fluids ?

Our puppy was prescribed 200ml of sub q ( Lactated ringers.) Every 4-6 Hrs. When I called out regular vet ( He was treated @ an emergency clinic.) to get a refill on his fluid our vet was concerned he is being overdosed with sub qs, so were going in tomorrow to have him looked at again. I called the emergency vet with worries about this and they insist I continue to use the sub qs even if he still has some left in his skin ( I can see a large amount of fluid still under his skin,) But I'm going with my regular vets suggestion and stopping the sub qs and letting him drink on is own which he is doing now ... So what are the complications over using to much fluids ? Could these complications already have hurt him ? ( He's been on sub qs starting Sunday, 26th - Wen - 30th