What is the daily maintenance fluid rate for horses or cows?

• A. 60 ml/kg/day
• B. 50 ml/kg/day
• C. 40 ml/kg/day
• D. 45 ml/kg/day

Answer: (B)

Maintenance fluid rate is the baseline amount of fluid needed to cover normal daily losses for a healthy adult animal. For horses and cows, the commonly used maintenance rate is about 50 ml per kilogram per day. That means a 500-kg horse would need roughly 25 liters of fluids per day (about 1 liter per hour). This rate reflects typical losses through urine, feces, and insensible routes, and is the standard starting point before adding deficits or accounting for ongoing losses. It can be increased with fever, sweating, lactation, or high activity, and decreased if intake is poor or there are organ issues.