Veterinary Drug Dosage Calculator (Dog, Cat, Horse)
A quick reference for the most common drugs used in small animal and equine practice. Pick a species, enter the patient's weight, search for the drug, and get the calculated mg dose and mL volume at standard product concentrations - with formulary notes and species-specific cautions.
Species
Patient weight (kg)
Drug
How to use this tool
What's included
Around 30 of the most-used drugs across nine categories: antibiotics (amoxicillin, doxycycline, enrofloxacin, metronidazole, clindamycin), NSAIDs (meloxicam, carprofen, robenacoxib, grapiprant), opioids (methadone, buprenorphine, tramadol), sedatives (dexmedetomidine, acepromazine, midazolam), anti-emetics (maropitant, ondansetron, metoclopramide), anti-parasitics (praziquantel, fenbendazole), emergency drugs (epinephrine, atropine, naloxone), corticosteroids (dexamethasone, prednisolone), and cardiac drugs (furosemide, pimobendan).
Where the numbers come from
Dose ranges are drawn from Plumb's Veterinary Drug Handbook (10th edition) and current FDA-approved product inserts. We use conservative published ranges rather than the most aggressive doses you might see in specialty practice.
Important: not a substitute for clinical judgement
This is a quick-look tool, not a prescribing system. Always confirm with your formulary, account for renal/hepatic status, body condition, and concurrent medications, and check for contraindications (NSAIDs in dehydration, opioids in respiratory compromise, fluoroquinolones in growing dogs, etc.). For controlled drugs, follow your local recording requirements.
Frequently asked questions
How does this drug dosage calculator work?
Pick a drug, pick the species, enter the patient's weight in kg, and the calculator multiplies through the published low/high mg/kg range. The output is the total mg or mL dose plus the formulary dosing notes. Doses are conservative defaults - always cross-check with your formulary and species-specific contraindications.
Is this safe to use clinically?
It's a starting point, not a substitute for clinical judgement. Numbers are drawn from Plumb's Veterinary Drug Handbook and product inserts. Confirm against your formulary, check for contraindications (e.g. NSAIDs in dehydrated patients, opioids in respiratory compromise), and adjust for renal/hepatic status.
Why are some drugs contraindicated in cats?
Cats lack key glucuronidation enzymes, so drugs that rely on that pathway accumulate. Paracetamol is the classic example - even a single dog-strength dose can be lethal. The calculator flags species-specific cautions where they apply.
Can owners use this for their own pet?
No. Always consult a veterinarian before giving any medication. Wrong dose, wrong drug, or wrong species combinations can cause serious harm. This tool is for licensed veterinary professionals.