Neostigmine: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Neostigmine methylsulfate, Prostigmin, Stiglyn

Species with doses

Dogs, Cats, Cattle, Horses, Goats, Sheep and Pigs

General dose range

0.02–0.04 mg/kg IM as needed — check the species tables for the indication

Routes

IM, SC

Last reviewed

1 October 2026

Indications

• Reversal of non-depolarising neuromuscular blockade (atracurium)
• Diagnosis and short-term treatment of myasthenia gravis
• Large-colon ileus (horses); rumen atony (ruminants)

Neostigmine dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Myasthenia gravis — diagnostic test: Papich 5e: 40 µg/kg IM or 20 µg/kg IV. Plumb’s p.886 (LeCouteur): 0.05 mg/kg IM — improvement within 15–30 min supports MG; pre-treat with atropine.
• Myasthenia gravis — parenteral treatment (regurgitating): Plumb’s p.886 (Inzana 2000): 0.04 mg/kg IM q6h until oral pyridostigmine can be given. Papich 5e: 10 µg/kg IM or SC as needed (not for long-term use); oral 2 mg/kg/day divided.
• Reversal of neuromuscular blockade: Papich 5e: 40 µg/kg IM or SC as an antidote for neuromuscular blockade. Give only once recovery has begun (train-of-four); ventilate until adequate.

Cats

• Myasthenia gravis / NMB reversal: Plumb’s p.886 (Inzana 2000): 0.04 mg/kg IM q6h for regurgitating cats. Papich 5e (dogs and cats): reversal 40 µg/kg IM or SC; diagnosis 40 µg/kg IM or 20 µg/kg IV.

Cattle

• Rumen atony / GI stimulation: Papich 5e: 22 µg/kg SC; rumen motility 0.02 mg/kg IM or SC. Plumb’s p.886 (label): 1 mg per 100 lb SC. Rule out obstruction first. Follow the local label or FARAD for withdrawal.

Horses

• Large-colon ileus / NMB reversal: Papich 5e: 0.02–0.04 mg/kg IV or SC, or CRI 0.008 mg/kg/h. Plumb’s p.886: 0.022 mg/kg IV or 0.044 mg/kg SC/IM — no value in small-intestinal ileus (White); 0.025 mg/kg SC q2–6h (Hassel); 2 mg per 500 kg every 30–60 min to 10 mg total (Hallowell). May cause colic. ARCI Class 3.

Goats

• Rumen atony / GI stimulation: Plumb’s p.886 (Davis 1986, sheep and goats): 0.01–0.02 mg/kg.

Sheep

• Rumen atony / GI stimulation: Papich 5e: 22–33 µg/kg SC. Plumb’s p.886: 1–1.5 mg per 100 lb SC (label); 0.01–0.02 mg/kg (Davis).

Pigs

• GI stimulation: Papich 5e: 44–66 µg/kg IM. Plumb’s p.886: 2–3 mg per 100 lb IM (label); 0.03 mg/kg (Davis).

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Rumen atony / GI stimulation: Papich 5e: 22 µg/kg SC; rumen motility 0.02 mg/kg IM or SC. Plumb’s p.886 (label): 1 mg per 100 lb SC. Rule out obstruction first. Follow the local label or FARAD for withdrawal.

Contraindications

Mechanical GI or urinary obstruction, peritonitis, bradycardia or AV block, asthma/bronchospasm. Do not use for small-intestinal ileus in horses (no benefit, colic). Depolarising blockers (succinylcholine) are prolonged, not reversed.

Adverse effects

• Salivation, diarrhoea, urination (muscarinic)
• Bradycardia
• Bronchospasm
• Muscle fasciculation / cholinergic weakness at high doses
• Colic (horses)

Toxicity and overdose

Management: Cholinergic crisis (salivation, diarrhoea, bradycardia, weakness): atropine 0.02–0.04 mg/kg IV/IM, ventilatory support.

Formulations and products

• Injection 0.5 mg/mL
• Injection 2 mg/mL (1:500, large animal)

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other hormones, emergency drugs, supplements and other drugs

• Mycophenolate Mofetil
• N-Acetylcysteine (NAC)
• Naloxone HCl
• Nandrolone Decanoate
• Oclacitinib
• Octreotide
• Oral Calcium / Phosphorus Bolus (Calcimust)
• Oral Iron + B12 + Folic Acid (Feritas / Ferikind)

Frequently asked questions