Calculation of 24-Hour Fluid Requirement at Different Levels of Dehydration

*% Dehydration*	Rehydration Needs(a) (ml/kg/day)	Maintenance Needs(b) (ml/kg/day)	Total Requirement(c) (ml/kg/day)	Multiplication Factor (d) (x Maintenance)
1	10	60	70	1.2
2	20	60	80	1.3
3	30	60	90	1.5
4	40	60	100	1.7
5	50	60	110	1.8
6	60	60	120	2.0
7	70	60	130	2.2
8	80	60	140	2.3
9	90	60	150	2.5
10	100	60	160	2.7
11	110	60	170	2.8
12	120	60	180	3.0
a Fixed relationship of 10 ml/kg/day required for each percentage point of dehydration. b Average maintenance requirement assuming no additional contemporary losses of fluid. This amount may need to be adjusted upward to account for contemporary losses, such as vomiting, diarrhea, and polyuria. c Total requirement equals sum of rehydration and maintenance needs. d Alternative method of calculation of total fluid requirement multiplies this arithmetic factor times the maintenance requirement of 60 ml/kg/day; thus, most dehydrated cats will require two times (moderate or 6 percent dehydration) to three times (severe or 12 percent dehydration) maintenance volume. Note: Water intake from food and drinking must be taken into consideration while calculating the fluid requirement. One, 5.5 oz can of cat food that contains 75% moisture contains 143 ml of water.