Successful fluid therapy results in the improvement or normalization of mental status, mucous membrane color, pulse rate, blood pressure. Another indicator is the capillary refill time, which can determine the blood flow to the tissue. Start by lifting the cat’s upper lip and pressing your finger against the gum tissue. Once you remove the pressure you should see a white mark on the guns where your finger was, and using the second hand on a watch, time how long it takes for the pink color to return to the white mark where your finger was. For a healthy cat, it should take somewhere between 1-2 seconds for the pink color to return.