Hydration measures in cats during brief anesthesia: intravenous fluids versus pre-procedure water supplement ingestion
Zanghi, B.M. et al.
2019
American Journal of Veterinary Research

This study demonstrated that cats ingesting a nutrient-enriched water supplement 2-3 hrs prior to anaesthesia will begin the procedure better hydrated as determined by a significant increase of 0.9% total body water (TBW) prior to intervention.
In addition, cats that ingested the supplement appear to be equally hydrated compared to cats administered intra-venous fluids (IV) or better hydrated than cats with no IV fluids, following completion of a brief anaesthetic procedure.