A 4 kg cat has 7% dehydration. Estimated fluid deficit is which of the following?

• A. 0.28 liters
• B. 0.04 liters
• C. 0.70 liters
• D. 0.07 liters

Answer: (A)

Estimation of fluid deficit uses the percentage of dehydration and the animal’s body weight. The deficit equals the percent dehydration times the body weight, with 1 liter of water weighing about 1 kilogram, so the result is in liters.

For a 4 kg cat with 7% dehydration: 0.07 × 4 kg = 0.28 kg ≈ 0.28 liters (280 mL). Thus, the estimated deficit is 0.28 liters.

The other values correspond to different dehydration percentages: 0.04 liters is about 1% dehydration (0.04 × 4 = 0.16? wait—0.01 × 4 = 0.04), 0.70 liters would be about 17.5% dehydration (0.70 ÷ 4 = 0.175), and 0.07 liters is about 1.75% dehydration.