Cat · Felis catus · typical adult weight 2.50–7.00 kg
Methadone is dosed at 0.1–0.3 mg/kg IM q4-6h in cats, per Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.872 (2026-08-01). — Plumb's 10th ed (held) printed p.842, Methadone monograph spanning p.842-845; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Methadone is used in cats for Perioperative analgesia. Routes documented in cats: IM. A typical adult cat weighs 2.50–7.00 kg. ExoticRx lists 1 cited dose rule for Methadone in cats, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Methadose
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| IM | 0.1–0.3 mg/kg | q4-6h | Perioperative | Perioperative analgesia | Strong | Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.872 (2026-08-01). — Plumb's 10th ed (held) printed p.842, Methadone monograph spanning p.842-845; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |
Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.
The sources disagree for this combination. The ranges below do not overlap on a comparable route. This is not an error in one of them — published veterinary references differ, and reconciling them for a particular patient is a clinical judgement.
| Dose (%) | Route | Source | As printed |
|---|---|---|---|
| 50 | — | Papich Saunders Handbook of Veterinary Drugs, 4th edp.531 | than 50% absorption. |
| Dose (mg/kg) | Route | Source | As printed |
|---|---|---|---|
| 0.1–0.5 | IM | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.271 | 0.1-0.5 mg/kg i.m. or 0.1-0.3 mg/kg i.v. prn. Doses in the range of 0.6 mg/kg are appropriate for oral |
| 0.1–0.3 |
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Full mu-opioid receptor agonist providing analgesia. Also antagonizes NMDA receptors and inhibits serotonin/norepinephrine reuptake, contributing to multimodal analgesia.
Respiratory depression. Bradycardia. No histamine release (advantage over morphine). NMDA antagonism provides wind-up prevention. Controlled substance (Schedule II). Dogs and cats.
Species-specific contraindications and adverse-reaction reports for cats may differ from canine / feline reference data — consult the primary citations listed with each rule.
Methadone dose range in cats, with cited source references: IM 0.1–0.3 mg/kg q4-6h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Methadone in cats: IM.
Cited course lengths for Methadone in cats include: Perioperative. Duration depends on the indication — match it to the specific dose rule in the table above.
Methadone is indicated in cats for: Perioperative analgesia.
These are general warnings for Methadone across species; consult the cat dosing table above for species-specific guidance. Respiratory depression. Bradycardia. No histamine release (advantage over morphine). NMDA antagonism provides wind-up prevention. Controlled substance (Schedule II). Dogs and cats.
Why a species-specific page? Methadone pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in cats — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.
| IV |
| BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.271 |
| 0.1-0.5 mg/kg i.m. or 0.1-0.3 mg/kg i.v. prn. Doses in the range of 0.6 mg/kg are appropriate for oral transmucosal administr |
| 0.6 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.271 | mg/kg i.m. or 0.1-0.3 mg/kg i.v. prn. Doses in the range of 0.6 mg/kg are appropriate for oral transmucosal administration in cats. |
| 0.3–0.6 | IV | Papich Saunders Handbook of Veterinary Drugs, 4th edp.531 | • 0.3-0.6 mg/kg q3-4h IV, SQ, or IM. Cats have tolerated doses up to 0.6 mg/kg |
| 0.6 | IV | Papich Saunders Handbook of Veterinary Drugs, 4th edp.531 | • 0.3-0.6 mg/kg q3-4h IV, SQ, or IM. Cats have tolerated doses up to 0.6 mg/kg |
Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.