Paracetamol (Acetaminophen): veterinary dose and monograph

At a glance

Drug class

Analgesic

Also known as

Acetaminophen, Crocin, Calpol, Dolo, Metacin, APAP

Species with doses

Dogs, Horses, Pigs, Guinea pigs, Rats, Mice and Primates

General dose range

10–15 mg/kg PO q8–12h — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Mild–moderate pain in dogs (musculoskeletal, post-operative adjunct)
• Pyrexia (antipyretic) in dogs
• Multimodal analgesia (often as paracetamol + codeine)

Paracetamol (Acetaminophen) 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

• Pain / pyrexia: Papich 5e: 15 mg/kg q8h PO. Plumb’s p.24: 15 mg/kg PO q8h (Dodman; McLaughlin); 10 mg/kg q12h (Kelly); 10–15 mg/kg q12h for 5 days (Gaynor 2008). Do not exceed 15 mg/kg q8h; hepatotoxic in overdose. CONTRAINDICATED IN CATS. For paracetamol–codeine combination tablets, Plumb’s doses by the codeine component — see Codeine.

Cats

• CONTRAINDICATED: Papich 5e: contraindicated in cats. Even one human tablet can kill a cat (deficient glucuronidation → methaemoglobinaemia, Heinz-body anaemia, facial oedema, hepatic necrosis). Treat exposure as an emergency (acetylcysteine).

Horses

• Analgesia (adjunct): Papich 5e: horses 20 mg/kg PO per day.

Pigs

• Miniature/pet pig — pyrexia / mild pain: Carpenter Exotic Animal Formulary 6th ed, Table 12-5 (p.668): miniature pigs 15 mg/kg PO q8h; or 325–500 mg/adult pig PO q8–12h.

Guinea pigs

• Post-operative / mild pain: Carpenter's 6th ed (Rodent analgesic table): 1–2 mg/mL in drinking water (all rodents); oral dosing extrapolated from rats (100–200 mg/kg PO).

Rats

• Post-operative / mild pain: Carpenter's 6th ed (Rodent analgesic table): rats 100–200 mg/kg PO (or 50–100 mg/kg SC); effective for post-operative pain. Also given as 1–2 mg/mL in drinking water. Rodents — unlike cats — tolerate acetaminophen; still watch for hepatotoxicity at high/repeated doses. Plumb’s p.24 (Adamcak & Otten 2000): rodents 1–2 mg/mL in drinking water for low-grade pain.

Mice

• Post-operative / mild pain: Carpenter's 6th ed (Rodent analgesic table): mice/rats ~200 mg/kg PO; or 1–2 mg/mL in drinking water for all rodents.

Primates

• Pyrexia / mild pain (New World primates): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.691): New World primates/marmosets/juvenile macaques 5–10 mg/kg PO q6h; monkeys 6 mg/kg PO q8h; prosimians 10–15 mg/kg PO q8–12h.

Contraindications

CATS — never, at any dose (fatal methaemoglobinaemia/hepatotoxicity). Pre-existing hepatic disease. Concurrent other hepatotoxins. G6PD-type oxidative susceptibility. Dehydration. Do not combine with other paracetamol-containing products (overdose).

Species-specific warnings

Cats: ABSOLUTELY CONTRAINDICATED. Cats cannot glucuronidate paracetamol — methaemoglobinaemia, Heinz-body anaemia and fatal hepatic necrosis from a single dose. Antidote is N-acetylcysteine; act immediately on any exposure.

Adverse effects

• Hepatotoxicity (dose-related, especially overdose)
• Methaemoglobinaemia (cyanosis, brown blood) — catastrophic in cats
• GI upset
• Keratoconjunctivitis sicca (reported, rare)

Drug interactions

• Other hepatotoxic drugs / enzyme inducers (phenobarbital): increased toxic metabolite (NAPQI) formation
• Warfarin: chronic high-dose paracetamol can potentiate anticoagulation
• Do not combine with other paracetamol-containing analgesics (additive overdose)

Pregnancy and lactation

Used cautiously and short-term in pregnant dogs; generally regarded as one of the safer analgesics in pregnancy in species that can metabolise it. Never in cats regardless.

Monitoring

• Liver enzymes (ALT/AST/bilirubin) on overdose or repeated dosing
• Mucous-membrane colour / methaemoglobin (cyanosis = emergency)
• PCV (Heinz-body anaemia after toxicosis)
• Ensure owners understand the absolute feline contraindication

Toxicity and overdose

Dogs: hepatotoxicity dominates at overdose (>100 mg/kg), with methaemoglobinaemia at higher doses. CATS: toxic at ~10 mg/kg and frequently fatal — methaemoglobinaemia (chocolate-brown blood, facial/paw oedema, cyanosis), Heinz-body anaemia and hepatic necrosis. The toxic metabolite is NAPQI, which depletes glutathione.

Management: Antidote: N-acetylcysteine (NAC) — loading 140 mg/kg PO/IV then 70 mg/kg q6h × 7+ doses (replenishes glutathione). Add decontamination (emesis/activated charcoal if early), IV fluids, ascorbic acid (vitamin C) and S-adenosylmethionine (SAMe) to combat methaemoglobinaemia/hepatic injury; oxygen and, if severe, blood/methylene-blue considerations (methylene blue is risky in cats). Monitor liver values and methaemoglobin.

Clinical pearls

• A genuinely useful canine analgesic — but the headline message is NEVER IN CATS (one tablet can kill)
• Pairs well with codeine for multimodal pain control in dogs
• Keep NAC stocked: it is the antidote for both canine overdose and the all-too-common feline poisoning
• Counsel owners to keep human paracetamol/Crocin/Dolo away from cats and never self-medicate pets
• Less GI/renal risk than classic NSAIDs, but hepatotoxic — avoid in liver disease and don't stack paracetamol products

Mechanism of action

Not fully resolved: it inhibits prostaglandin synthesis predominantly within the central nervous system (a relatively CNS-selective COX effect, with possible COX-2/peroxidase and "COX-3" contributions) and modulates serotonergic descending pain pathways and the endocannabinoid system via its AM404 metabolite. Weak peripheral anti-inflammatory action, hence less GI/renal NSAID toxicity but real hepatotoxicity.

Formulations and products

• 500 mg tablet
• 650 mg tablet
• Paediatric syrup 120 mg/5 mL (24 mg/mL)
• Paediatric drops 100 mg/mL
• IV infusion 10 mg/mL
• Mloxvet-P (Assure Biotech, Jagadhri (HR)) — Paracetamol 150 mg + Meloxicam 5 mg per mL, Fixed combination injection
• Nimusure-P (Assure Biotech, Jagadhri (HR)) — Paracetamol 150 mg + Nimesulide 100 mg per mL, Fixed combination injection
• Dolopar Vet Injection (Micro Animal Health Care (Micro Labs group), Bengaluru) — Paracetamol 150 mg + Meloxicam 5 mg + Lignocaine 1 % v/v per mL, Fixed combination injection
• Dolopar Vet Bolus (Micro Animal Health Care (Micro Labs group), Bengaluru) — Paracetamol 1500 mg + Meloxicam 100 mg, Oral bolus
• Crocin — 500 / 650 mg tablet; 120 mg/5 mL syrup, Tablet / syrup (human-label)
• Dolo 650 — 650 mg tablet, Tablet (human-label)
• Calpol — 120 mg/5 mL syrup; 250 mg tablet, Syrup / tablet (human-label)
• Paracetamol IV (Pacimol/Febrinil) — 10 mg/mL (1 g/100 mL), IV infusion (human-label)

Storage

Tablets/syrup: 15–30 °C, dry. IV: protect from light, single use.

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 analgesics

• Lidocaine HCl
• Methadone
• Morphine Sulfate
• Nalbuphine
• Pethidine (Meperidine)
• Pregabalin
• Tramadol

Frequently asked questions