ExoticRx · exoticrx.com/drugs/morphine
Morphine is dosed at 5–10 mg/kg IM single dose in the trial in argentine tegus, per Leal WP, Carregaro AB, Bressan TF, Bisetto SP, Melo CF, Sladky KK. Antinociceptive efficacy of intramuscular administration of morphine sulfate and butorphanol tartrate in tegus (Salvator merianae). Am J Vet Res. 2017;78(9):1019-1024. doi:10.2460/ajvr.78.9.1019 https://pubmed.ncbi.nlm.nih.gov/28836839/. Verify against current literature before clinical use.
Prototype full mu-opioid receptor agonist. Activates mu, kappa, and delta opioid receptors producing analgesia, sedation, and euphoria.
Histamine release with rapid IV injection (hypotension, bronchoconstriction — give slowly). Vomiting and defecation common initial effects. Respiratory depression. Cats: may cause excitation/dysphoria at higher doses. Controlled substance (Schedule II).
Controlled substance in the US
Controlled-drug status and schedules differ by country — check your local scheduling rules.
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
Morphine CRI dose rule from the ExoticRx formulary. Verify against current literature before clinical use; CRI rates differ from bolus dosing and route, dilution, and monitoring matter. Sign in for the complete per-species CRI protocol set.
| Species | Route | Rate | Indication | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | IV | 0.1–0.5 mg/kgq2-4h bolus or 0.1-0.3 mg/kg/h CRI | Severe pain, CRI | Strong | Lucas AN, Firth AM, Anderson GA, Vine JH, Edwards GA. Comparison of the effects of morphine administered by constant-rate intravenous infusion or intermittent intramuscular injection in dogs. J Am Vet Med Assoc. 2001;218(6):884-891. doi:10.2460/javma.2001.218.884 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.937 (2026-08-01). — Plumb's 10th ed (held) printed p.907, Morphine monograph spanning p.907-911; 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 |
A dog/cat sample is shown here. Cited dosing for all 28 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | IV | 0.1–0.5 mg/kg | q2-4h bolus or 0.1-0.3 mg/kg/h CRI | Strong | Lucas AN, Firth AM, Anderson GA, Vine JH, Edwards GA. Comparison of the effects of morphine administered by constant-rate intravenous infusion or intermittent intramuscular injection in dogs. J Am Vet Med Assoc. 2001;218(6):884-891. doi:10.2460/javma.2001.218.884 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.937 (2026-08-01). — Plumb's 10th ed (held) printed p.907, Morphine monograph spanning p.907-911; 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 |
| Dog (Domestic) | EPIDURAL | 0.1 mg/kg | Single injection |
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View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.
Species references:All African Clawed Frog drugsAll Argentine Tegu drugsAll Axolotl drugsAll Bearded Dragon drugsAll Betta (Siamese fighting fish) drugsAll Cat (Domestic) drugsAll Chicken (Poultry) drugsAll Chinchilla drugsAll Degu drugsAll Dog (Domestic) drugsAll Dwarf Hamster drugsAll Eastern Box Turtle drugsAll Ferret drugsAll Fire Salamander drugsAll Goldfish drugsAll Green Iguana drugsAll Guinea Pig drugsAll Houston Toad drugsAll Koi drugsAll Mouse drugs
Severe pain, CRI
| Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy), Morphine monograph, printed p.910 (corpus plumb p.937), DOGS - Analgesia (extra-label), item c) Epidural. - SOURCE EDITION: Plumb's Veterinary Drug Handbook - ISBN 9781394172207 |