About the Metacam Dosage Calculator for Cats
Metacam is a brand of meloxicam, a non-steroidal anti-inflammatory drug (NSAID) used to control pain and inflammation. In cats it is used for osteoarthritis pain and for post-operative pain after procedures like spays and dental work. Because it is dosed by body weight, this tool converts a cat's weight and the veterinarian's prescribed dose into two numbers you actually need at the point of care: the milligrams of active drug and the millilitres of liquid suspension to draw up.
Safety first: The feline Metacam oral suspension carries an FDA boxed warning. Repeated oral use of meloxicam in cats has been associated with acute kidney injury and death. This calculator is an arithmetic aid for a dose your veterinarian has already prescribed — it is not medical advice and is not a substitute for veterinary judgment. Never start, increase, or continue meloxicam in a cat without a vet's direction.
The formula
The calculation is a two-step multiplication that every weight-based liquid medication uses:
- Dose (mg) = body weight (kg) × dose rate (mg/kg). This gives the amount of active meloxicam.
- Volume (mL) = dose (mg) ÷ concentration (mg/mL). This converts the drug amount into a measurable volume of liquid.
If your cat's weight is in pounds, it is first converted to kilograms using 1 kg = 2.2046 lb (so kg = lb ÷ 2.2046). The feline Metacam oral suspension is 0.5 mg/mL, which is the default concentration here.
Concentrations and products — the critical distinction
Meloxicam suspension comes in more than one strength, and mixing them up is the single most dangerous mistake with this drug:
- Feline Metacam oral suspension: 0.5 mg/mL. This is the product intended for cats.
- Canine Metacam oral suspension: 1.5 mg/mL. This is three times as concentrated. Giving a cat the same volume using the dog bottle delivers three times the intended dose.
- Feline Metacam injectable: 5 mg/mL, used by veterinarians for the one-time subcutaneous dose, not for at-home oral use.
Always read the label strength and match it to the field in this calculator. If you enter a concentration of 1.5 or higher, the tool flags it as the dog-strength product.
Common reference doses
- FDA-approved feline use: a single, one-time subcutaneous injection of 0.3 mg/kg meloxicam, given by a veterinarian, typically for post-operative pain.
- Off-label oral protocol (veterinary formularies such as Plumb's): approximately 0.1 mg/kg on the first day, then 0.05 mg/kg once daily as a maintenance dose, at the lowest effective level.
Worked example: a 4 kg cat at the 0.05 mg/kg maintenance rate needs 4 × 0.05 = 0.2 mg, which at 0.5 mg/mL is 0.2 ÷ 0.5 = 0.4 mL of the feline suspension. At the 0.1 mg/kg loading rate the same cat would need 0.4 mg = 0.8 mL.