VETINUITY
Is one ibuprofen tablet dangerous for a small dog?
A 200 mg tablet is 100 mg/kg for a 2 kg dog, the dose where acute GI signs start. Put the weight and tablet count into the calculator above.
● ANSWER
Sourced & dated
How much ibuprofen or naproxen is toxic to a dog?
Ibuprofen causes GI signs in dogs from 100-125 mg/kg, renal failure from 175-300 mg/kg, CNS signs above 400 mg/kg and can be lethal above 600 mg/kg; naproxen is toxic at far lower doses.
● VETINUITY IBUPROFEN EXPOSURE CALCULATOR
Vetinuity ibuprofen exposure calculator
Ibuprofen bands for dogs. Cats reach the same effects at about half these doses. Naproxen does not fit these bands.
● WHAT'S DOCUMENTED
Vetinuity’s NSAID overdose table puts a single ibuprofen ingestion in a dog at GI signs from 100 to 125 mg/kg, renal failure from 175 to 300 mg/kg, CNS signs above 400 mg/kg and potential death above 600 mg/kg, while naproxen causes bleeding ulcers at a single 35 mg/kg dose. The Vetinuity ibuprofen exposure calculator above turns tablets and body weight into mg/kg and the matching band. It belongs to the toxicology set Brian Toncray, DVM, an emergency veterinarian, built into the Vetinuity clinical assistant.
Toxic doses by drug
| Drug | Dose in dogs | Effect |
|---|---|---|
| Ibuprofen | 8-16 mg/kg daily for 30 days | Gastric ulceration or erosions |
| Ibuprofen | 100-125 mg/kg once | Vomiting, diarrhea, abdominal pain |
| Ibuprofen | 175-300 mg/kg once | Renal failure |
| Ibuprofen | Over 400 mg/kg once | Seizures, ataxia, coma plus renal and GI injury |
| Naproxen | 5.6 mg/kg daily for 7 days | Vomiting, tarry feces, weakness |
| Naproxen | 35 mg/kg once | Hematemesis, melena, abdominal pain |
| Aspirin | 450 mg/kg once | GI signs, hyperthermia, seizures, coma |
Cats are poisoned by ibuprofen at about half the canine dose and handle naproxen and aspirin worse than dogs because of their limited glucuronide conjugation.
Decontamination
Induce emesis in a dog that is still clinically normal, then give activated charcoal with a cathartic. Naproxen and massive ibuprofen ingestions recirculate through bile, so the single charcoal dose is followed by oral cholestyramine every 6 to 8 hours for 3 days, watching sodium for hypernatremia. Plasma exchange has rescued several massive naproxen overdoses. Do not induce emesis in a dog that is already depressed or seizing.
Protecting the stomach and kidneys
- Misoprostol 1-3 mcg/kg PO every 6 to 8 hours in dogs, shown to prevent NSAID-induced ulceration.
- An H2 blocker such as famotidine, or omeprazole 0.5-1 mg/kg PO every 24 hours.
- Sucralfate 250-500 mg total per dose in small dogs, 1 g total per dose in large dogs, divided every 6 to 12 hours.
- IV fluid diuresis, with renal values at baseline, 24, 48 and 72 hours.
- Maropitant 1 mg/kg every 24 hours or ondansetron 0.5-1 mg/kg every 12 hours for vomiting.
Intravenous fat emulsion for large ingestions
For massive ibuprofen ingestions with neurologic signs, IV fat emulsion has been used successfully in people and animals. The usual protocol is 1.5 mL/kg of 20% emulsion over 5 to 15 minutes, then 0.25 mL/kg/min for 1 to 2 hours, repeated if signs return and the serum is not lipemic.
Related: acetaminophen toxicity, xylitol and rodenticide.
● SOURCES
- 1. Merck Veterinary Manual: Toxicoses From Human Analgesics in Animals. Aspirin; Ibuprofen; Naproxen; treatment and IV fat emulsion. Checked 2026-10-26.
● RELATED ANSWERS
- Acetaminophen Toxicity in Cats and Dogs: NAC Dose
Cats are poisoned at 40-50 mg/kg and can show signs at 10 mg/kg; dogs above 100 mg/kg. Treat with N-acetylcysteine 140 mg/kg IV or PO, then 70 mg/kg PO every 6 hours for 5 to 7 more doses.
- Rat Poison in Dogs: Vitamin K1 Dose and Duration
Vitamin K1 at 2.5 mg/kg PO every 12 hours or 5 mg/kg PO every 24 hours for four weeks with a fatty meal, then a PT check after the last dose.
- Grape and Raisin Toxicity in Dogs: Treatment
More than one grape or raisin per 4.5 kg can carry enough tartaric acid to injure the kidneys: induce emesis in a normal dog, run IV fluids for at least 48 hours, and follow creatinine for 72 hours.
- Xylitol Toxicity in Dogs: Treatment
Canine xylitol toxicity: insulin-mediated hypoglycemia and hepatopathy, with decontamination, monitoring, and prognosis from published case series.
- Dog Ate Chocolate: Assessment and Treatment
Contact a veterinarian promptly with the chocolate type, amount and exposure time; chocolate toxicosis assessment depends on the dog’s weight and the methylxanthine exposure.
● FAQ
Why is naproxen worse than ibuprofen?
Naproxen has a 74-hour half-life in dogs from enterohepatic recirculation. A single 35 mg/kg dose has caused hematemesis and melena.
How long do I monitor kidney values?
Check baseline renal values and recheck at 24, 48 and 72 hours.
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