ExoticRx · exoticrx.com/drugs/methocarbamol-injectable
US brand names:Robaxin-V Injectable
Methocarbamol Injectable is dosed at 44–150 mg/kg IV Slow IV to effect; may repeat in cats, per Plumb's Veterinary Drug Handbook, 10th ed, Methocarbamol monograph, corpus PDF p.882. DOGS/CATS (label dosage, FDA-approved): Injectable - "For relief of moderate conditions: 44 mg/kg IV initial dose"; "For controlling severe effects of strychnine and tetanus: 55 - 220 mg/kg IV initial dose... The […]" Oral (tablets) - "132 mg/kg PO on Day 1 in 2 or 3 equally divided doses (ie, every 8 to 12 hours), then 66 - 132 […]" DOGS, intervertebral disk disease (extra-label): "Anecdotal dosages of 15 - 20 mg/kg PO every 8 hours are usually noted." HORSES (label dosage, FDA-approved): "For moderate conditions: 4.4 - 22 mg/kg IV to effect"; "For severe conditions (tetanus): 22 - 55 mg/kg IV". — SOURCE ROWS: Plumb's Veterinary Drug Handbook, Methocarbamol monograph, corpus p.882, DOGS/CATS (label dosage, FDA-approved), Injectable — "i. For relief of moderate conditions: 44 mg/kg IV initial dose. ii. For controlling severe effects […]" — RETRIEVED FINDING - CHANGE REQUIRED (retrieved 2026-08-19): Initially, 40 - 50 mg/kg IV slowly over 3 to 5 minutes to clinical effect (ie, resolution or near-resolution of clinical signs). Repeat as necessary or follow with a CRI at an initial rate of 10 mg/kg/hour IV. — Plumb's Veterinary Drug Handbook 10th ed, Methocarbamol, printed p.855 / corpus p.882 | ORIGINAL SOURCE THE BOOK CITES (2026-08-20): the dose row carries superscript 4 — "44 mg/kg IV initial dose4 should be used in nursing dams.9" — which resolves in the monograph's own reference list to: ROBAXIN-V INJECTION - Methocarbamol Injectable and Tablets [US Product Label for Dogs, Cats, and Horses]. Fort Dodge; 2003. This records what the handbook attributes the figure to. It is NOT a statement that the reference was read or that it validates the dose.. Verify against current literature before clinical use.
Centrally acting muscle relaxant that depresses polysynaptic reflexes in the spinal cord and subcortical areas, reducing skeletal muscle hypertonicity and spasm.
IV route for acute severe muscle spasm (tetanus, strychnine toxicity, metaldehyde). Administer slowly to avoid seizures. Sedation and ataxia expected. Do not exceed 330mg/kg/day.
Species references:All Cat (Domestic) drugsAll Dog (Domestic) drugs
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A dog/cat sample is shown here. Cited dosing for all 2 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 |
|---|---|---|---|---|---|
| Cat (Domestic) | IV | 44–150 mg/kg | Slow IV to effect; may repeat | Strong | Plumb's Veterinary Drug Handbook, 10th ed, Methocarbamol monograph, corpus PDF p.882. DOGS/CATS (label dosage, FDA-approved): Injectable - "For relief of moderate conditions: 44 mg/kg IV initial dose"; "For controlling severe effects of strychnine and tetanus: 55 - 220 mg/kg IV initial dose... The […]" Oral (tablets) - "132 mg/kg PO on Day 1 in 2 or 3 equally divided doses (ie, every 8 to 12 hours), then 66 - 132 […]" DOGS, intervertebral disk disease (extra-label): "Anecdotal dosages of 15 - 20 mg/kg PO every 8 hours are usually noted." HORSES (label dosage, FDA-approved): "For moderate conditions: 4.4 - 22 mg/kg IV to effect"; "For severe conditions (tetanus): 22 - 55 mg/kg IV". — SOURCE ROWS: Plumb's Veterinary Drug Handbook, Methocarbamol monograph, corpus p.882, DOGS/CATS (label dosage, FDA-approved), Injectable — "i. For relief of moderate conditions: 44 mg/kg IV initial dose. ii. For controlling severe effects […]" — RETRIEVED FINDING - CHANGE REQUIRED (retrieved 2026-08-19): Initially, 40 - 50 mg/kg IV slowly over 3 to 5 minutes to clinical effect (ie, resolution or near-resolution of clinical signs). Repeat as necessary or follow with a CRI at an initial rate of 10 mg/kg/hour IV. — Plumb's Veterinary Drug Handbook 10th ed, Methocarbamol, printed p.855 / corpus p.882 | ORIGINAL SOURCE THE BOOK CITES (2026-08-20): the dose row carries superscript 4 — "44 mg/kg IV initial dose4 should be used in nursing dams.9" — which resolves in the monograph's own reference list to: ROBAXIN-V INJECTION - Methocarbamol Injectable and Tablets [US Product Label for Dogs, Cats, and Horses]. Fort Dodge; 2003. This records what the handbook attributes the figure to. It is NOT a statement that the reference was read or that it validates the dose. |
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| Dog (Domestic) | IV | 44–220 mg/kg | Slow IV to effect; q8-12h, max 330 mg/kg/day | Strong | Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted), p.855 (corpus PDF p.882) — Methocarbamol, Dosages, DOGS/CATS, Injectable label dosage and extra-label tremorgenic-toxicity paragraph — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 — SOURCE ROWS: Plumb's Veterinary Drug Handbook, Methocarbamol monograph, corpus p.882, DOGS/CATS (label dosage, FDA-approved), Injectable — "i. For relief of moderate conditions: 44 mg/kg IV initial dose. ii. For controlling severe effects […]" | ORIGINAL SOURCE THE BOOK CITES (2026-08-20): the dose row carries superscript 4 — "44 mg/kg IV initial dose4 should be used in nursing dams.9" — which resolves in the monograph's own reference list to: ROBAXIN-V INJECTION - Methocarbamol Injectable and Tablets [US Product Label for Dogs, Cats, and Horses]. Fort Dodge; 2003. This records what the handbook attributes the figure to. It is NOT a statement that the reference was read or that it validates the dose. |