Cephalexin For Dogs Dosage Calculator

Cephalexin dosage estimator for dogs

This calculator estimates a cephalexin dosing plan based on your dog’s weight, a dose rate in mg/kg per administration, a dosing interval, and the planned duration. This tool is for vet review and planning only and does not replace a diagnosis or a prescription.

How the calculation works

The core calculation converts body weight into a per-dose amount:

\( \text{TargetDose(mg)} = \text{Weight(kg)} \times \text{DoseRate(mg/kg)} \)

If you enter weight in pounds, the calculator converts it to kilograms using:

\( \text{Weight(kg)} = \text{Weight(lb)} \div 2.20462 \)

Doses per day are derived from the chosen interval:

\( \text{DosesPerDay} = 24 \div \text{IntervalHours} \)

Then daily and course totals are computed from the rounded (practical) administered dose:

\( \text{TotalPerDay(mg)} = \text{DosePerAdministration(mg)} \times \text{DosesPerDay} \)

\( \text{TotalCourse(mg)} = \text{TotalPerDay(mg)} \times \text{DurationDays} \)

Tablets versus liquid suspension

Tablet/capsule mode converts mg into “units per dose” using the tablet strength (mg per unit). It then rounds the unit count to a practical step (whole, half, or quarter units) so you can see the real administered mg after rounding.

Liquid mode converts mg into mL per dose using the liquid concentration (mg/mL) and then rounds to a syringe-friendly increment (for example 0.1 mL).

These rounding choices can materially change the final mg/kg that is actually administered, so the schedule table includes a range check and highlights rows that require review.

Range checks and safety notes

Veterinary references list dosing ranges that vary by indication. Some sources list typical cephalexin ranges such as 15–45 mg/kg by mouth every 6–12 hours, while labeled regimens for specific products and indications may specify a particular dose such as 22 mg/kg twice daily for a defined treatment window. Always follow your veterinarian’s instructions, especially when they differ from defaults or presets.

The calculator flags “Review” if the rounded mg/kg falls outside a commonly referenced range or if the chosen interval is outside q6–12h patterns. This is a computational warning, not a clinical decision.

Practical usage tips

• Use the schedule to see every dose date and time across the planned duration.
• Use Customize Columns to prioritize the information you actually need (for example rounded mg, mL per dose, or mg/kg after rounding).
• Reset restores default inputs and also restores the default column order and visibility.

When to contact a veterinarian

If your dog has worsening symptoms, severe vomiting/diarrhea, facial swelling, trouble breathing, or any reaction that concerns you, seek veterinary care immediately. Antibiotic selection, dosing, and duration depend on the infection type, culture results, and your dog’s medical history.