Correct fluid therapy is a cornerstone of veterinary medicine for treating dehydration caused by illness, surgery, or trauma. This calculator utilizes the standard three-component approach to determine the Total Fluid Volume required:
Deficit Volume: The amount of fluid lost due to dehydration. Calculated as Weight (kg) × % Dehydration × 1000.
Maintenance Volume: The daily water requirement for normal metabolic function. This calculator uses the standard estimate of 60mL/kg/day for simplicity, though metabolic formulas (132 × kg0.75) are also common.
Ongoing Losses: Estimated fluids lost continuously through vomiting, diarrhea, or polyuria that must be replaced.
Estimating Dehydration Percentage
Accurately estimating the percentage of dehydration is critical for inputting the correct data:
< 5%: Not detectable clinically.
5-6%: Subtle loss of skin elasticity; mucous membranes slightly dry.
6-8%: Delayed skin tenting; dry mucous membranes; slight prolongation of capillary refill time (CRT).
10-12%: Skin remains tented; pale membranes; prolonged CRT; eyes sunken; signs of shock.
12-15%: Critical shock; death imminent without rapid intervention.
Drip Sets and Flow Rates
The "Drip Factor" depends on the administration set (IV line) being used.
Macrodrip sets (10, 15, or 20 drops/mL) are used for dogs over 10kg to allow faster flow.
Microdrip sets (60 drops/mL) are used for small dogs and puppies to allow for precise, slow delivery.
Veterinary Disclaimer: This calculator is a support tool for educational and estimation purposes only. It is not a substitute for professional veterinary judgment. Fluid rates must be adjusted based on the patient's cardiac and renal status. Always monitor the patient for signs of overhydration (chemosis, tachypnea, nasal discharge).
function calculateFluidRate() {
// 1. Get Inputs
var weightInput = document.getElementById('dogWeight').value;
var unit = document.getElementById('weightUnit').value;
var dehydrationInput = document.getElementById('dehydrationPct').value;
var lossesInput = document.getElementById('ongoingLosses').value;
var hoursInput = document.getElementById('hours').value;
var dripFactorInput = document.getElementById('dripFactor').value;
// 2. Validate Numbers
var weight = parseFloat(weightInput);
var dehydration = parseFloat(dehydrationInput);
var losses = parseFloat(lossesInput);
var hours = parseFloat(hoursInput);
var dripFactor = parseFloat(dripFactorInput);
if (isNaN(weight) || weight <= 0) {
alert("Please enter a valid weight.");
return;
}
if (isNaN(hours) || hours 0) {
secondsPerDrop = 60 / dripRate;
}
// 5. Update UI
document.getElementById('resWeightKg').innerText = weightKg.toFixed(2) + " kg";
document.getElementById('resDeficit').innerText = Math.round(deficitVolume) + " mL";
document.getElementById('resMaintenance').innerText = Math.round(timeframeMaintenance) + " mL (" + hours + " hrs)";
document.getElementById('resLosses').innerText = Math.round(losses) + " mL";
document.getElementById('resTotal').innerText = Math.round(totalVolume) + " mL";
document.getElementById('resHourly').innerText = hourlyRate.toFixed(1) + " mL/hr";
document.getElementById('resDripRate').innerText = Math.round(dripRate) + " gtt/min";
var timingText = "";
if (dripRate > 0) {
if (secondsPerDrop 1 drop/sec)";
} else {
timingText = "1 drop every " + secondsPerDrop.toFixed(1) + " seconds";
}
} else {
timingText = "No flow required";
}
document.getElementById('resTiming').innerText = timingText;
// Show result box
document.getElementById('resultArea').style.display = 'block';
}