Cephalexin Dosage Calculator for Cats

How to Calculate Cephalexin Dosage for Cats

This calculator determines a safe cephalexin dose for cats based on weight, using these formulas:

Dose per Administration (mg):

\[ \text{Dose (mg)} = \text{Weight (kg)} \times \text{Dose Base (converted to mg/kg)} \]

Daily Dose (mg):

\[ \text{Daily Dose (mg)} = \text{Dose (mg)} \times \text{Doses per Day} \]

Tablets: Divide mg by tablet strength (e.g., 250 mg), round to nearest 0.5 tablet.

Volume (mL, Oral Suspension):

\[ \text{Volume (mL)} = \frac{\text{Dose (mg)}}{\text{Strength (mg/mL)}} \]

Where:

\( \text{Weight} \): Cat’s weight in kilograms (kg), pounds (lb), or ounces (oz, converted to kg)
\( \text{Dose Base} \): mg/kg, g/kg (×1000), mg/lb (÷2.20462), or mg/oz (×35.274÷2.20462), converted to mg/kg
\( \text{Strength} \): Tablet size (mg) or suspension concentration (mg/5 mL, e.g., 125 mg/5 mL = 25 mg/mL)
\( \text{Doses per Day} \): 2 (every 12h), 3 (every 8h), or 4 (every 6h)

Dose is given every 6–12 hours, based on veterinary recommendation. Use only vet-prescribed cephalexin formulations, as it’s used off-label for cats.

Using the Cephalexin Dosage Calculator for Cats

This tool estimates a cephalexin dose for cats to treat bacterial infections like skin, soft tissue, urinary tract, or respiratory issues. Input the cat’s weight (kg, lb, or oz), specify the dose base (mg/kg, g/kg, mg/lb, or mg/oz), select the form and strength (tablet or oral suspension), and choose the dosing frequency. Results show the dose per administration, daily total in mg, tablets, or mL, and liquid amounts for suspension.

Example: 12 kg cat, Dose Base 15 mg/kg, Oral Suspension (125 mg/5 mL), Every 12 hours:

Every 12 hours:
📍 The calculated dosage is based on the MSD Manual recommendations.
Amount per dose:
In milligrams: 180 mg
In Oral Suspension (125 mg/5 mL): 7 mL
Daily dosage:
In milligrams: 360 mg
Amount of medicine:
Liquid per dose: 7 mL
Liquid per day: 14 mL
Dosing rules: 15 mg/kg per dose

Consult a veterinarian before administering to confirm the dosage and treatment plan, as cephalexin is used off-label for cats.

Frequently Asked Questions (FAQ)

1. What is cephalexin used for in cats?

Cephalexin is an antibiotic used off-label to treat bacterial infections in cats, such as skin and soft tissue infections, urinary tract infections, and respiratory issues.

2. How often should I give my cat cephalexin?

It’s typically given every 6–12 hours, with common frequencies of every 12 hours (twice daily), 8 hours (three times daily), or 6 hours (four times daily), as prescribed by a vet.

3. Can I use human cephalexin for my cat?

Yes, if prescribed by a veterinarian, but ensure it’s plain cephalexin (e.g., Keflex) without additional ingredients, as it’s not FDA-approved for cats and requires professional oversight.

4. What’s the difference between tablets and oral suspension?

Tablets (250 mg, 500 mg) are solid, easier for larger cats, while oral suspension (125 mg/5 mL, 250 mg/5 mL) is a liquid for precise dosing, especially for smaller cats or those unable to swallow pills.

5. How do I adjust if my suspension strength differs?

Divide the mg dose by your suspension’s mg/mL concentration (e.g., for 125 mg/5 mL = 25 mg/mL, 180 mg = 7.2 mL).

6. How long does cephalexin treatment last for cats?

Treatment typically lasts 5–14 days, depending on the infection’s severity, but follow your veterinarian’s prescribed duration, as it’s used off-label.