FrançaisIs ibuprofen toxic to dogs?
Yes. The Merck Veterinary Manual states that ibuprofen is no longer recommended in dogs, because it can cause stomach ulcers and perforations; stomach and gut bleeding and kidney damage are its most common toxic effects [1]. If your dog has swallowed ibuprofen, naproxen, aspirin or any human painkiller, call your vet or a pet poison line now, even if your dog seems fine. Keep the box: many cough and cold products also contain NSAIDs or acetaminophen, so the exact product matters [1].
Human NSAIDs are among the most common poisonings reported to animal poison control centers [1]. The ASPCA Animal Poison Control Center recorded 22,206 NSAID cases in dogs and cats from 2005 to 2010, and ibuprofen was the drug most often involved, followed by aspirin and naproxen [4].
How human NSAIDs harm a dog’s stomach and kidneys
NSAIDs block the cyclooxygenase enzymes (COX-1 and COX-2) that make prostaglandins [1]. In the gut and the kidneys, these prostaglandins do protective work [2]:
- Stomach and intestine: prostaglandins keep blood flowing to the stomach lining and drive the production of mucus and bicarbonate. Without them, stomach acid injures the lining and its blood vessels, which leads to erosions and ulcers [2]. Ulcers can bleed and, in severe cases, perforate [1].
- Kidneys: prostaglandins widen the kidney blood vessels when blood pressure or hydration drops. When they are blocked, blood flow to the kidneys falls and acute kidney injury can follow [2].
- Blood clotting: NSAIDs reduce the ability of platelets to clump; aspirin does this for the platelet’s whole life, which can prolong bleeding [1, 2].
- Brain: after very large amounts of ibuprofen, dogs can show seizures, wobbling, dullness or coma [1].
Ibuprofen is absorbed fast: blood levels peak 30 minutes to 3 hours after a dog swallows it [1]. Naproxen is a particular concern because dogs keep recycling it between the liver and the gut: its half-life in dogs is about 74 hours [1]. Medicines are not interchangeable between species, and a safe human dose cannot be converted into a safe dog dose [2].
Ibuprofen, naproxen and aspirin: reported toxic amounts
Vets and poison centers use published thresholds, in milligrams per kilogram of body weight, to judge the risk. These figures come from references and studies; they are not safe limits [1, 3]:
| Drug | Effects reported in dogs |
|---|---|
| Ibuprofen | Vomiting, diarrhea and belly pain after a single 100–125 mg/kg; kidney failure from 175–300 mg/kg; seizures and coma above 400 mg/kg; potentially lethal above 600 mg/kg [1] |
| Naproxen | Stomach effects above 5 mg/kg, kidney injury above 25 mg/kg and nervous signs above 50 mg/kg, as used in a 434-dog study [3]; one 220 mg tablet can cause very serious signs even in a large dog [13] |
| Aspirin | Vomiting, high temperature, panting, seizures or coma after a large single amount (450 mg/kg); ulcers with repeated use [1] |
Thresholds do not predict every dog. In a US poison center study of acute ibuprofen cases, no clear link between amount and outcome was found, and the authors advise that dogs swallowing even small amounts may need active care; Labradors had a lower risk of ulcers, and the authors suggest German Shepherds may be more susceptible [5]. In the 434-dog study, the 400 mg/kg ibuprofen threshold was a poor predictor of kidney injury [3]. Repeated use is also risky: with regular doses, ulcers and kidney damage are unpredictable [6]. Call your vet or a pet poison line whatever the amount.
Cats react to ibuprofen at about half the amount that harms dogs [1]. Acetaminophen (Tylenol) acts differently: it mainly damages the liver in dogs and the red blood cells in cats [6]. See acetaminophen and dogs and cats.
Signs and timing
Vomiting is the sign seen most often: it was the most common sign in 125 dogs seen at an emergency room after an NSAID overdose (46 dogs, 37%) [7]. Kidney injury often shows later, on blood tests rather than at home [3].
- Stomach and gut: vomiting, diarrhea, vomit with blood, black tarry stools (digested blood), loss of appetite, belly pain [12, 13].
- Blood loss: weakness and pale gums from anemia [13]. Bleeding can also be hidden and slowly cause iron-deficiency anemia [2]. In one reported case, a dog given naproxen by its owner for a stiff shoulder developed a bleeding stomach ulcer and needed a blood transfusion [14].
- Kidneys: at first more urine and more thirst, then in severe cases little or no urine [12].
- Brain, after large amounts: dullness, wobbling, seizures, coma [1].
- In real cases: of 225 dogs seen for ibuprofen at five US hospitals, 46% had digestive signs and 18% already had kidney injury when they arrived; during the hospital stay digestive signs rose to 60% and kidney injury to 35% [3].
Time matters. The longer the delay before treatment, the higher the risk of ulcers and of kidney failure [5]; arriving more than 7.5 hours after ingestion predicted kidney injury in the 434-dog study [3]. In dogs given fluids only, 10% developed kidney injury that was not there on arrival [3].
What the vet checks, and why
There is no quick clinic test for ibuprofen in the blood; the vet relies on what the dog swallowed and on the signs [8]. Blood and urine tests then show whether the stomach or kidneys are affected, and are repeated to follow the trend [1, 3].
- Abbreviation CREA, CREAT or creatinine: the kidney value repeated after an NSAID overdose [1, 3].
- Result 2.1 mg/dL in this illustrative line: IRIS acute kidney injury grade II (1.7–2.5 mg/dL) [9], the most frequent grade among ibuprofen dogs with kidney injury (39%) [3].
- Unit mg/dL in the US; µmol/L elsewhere: 2.1 mg/dL ≈ 186 µmol/L (× 88.4).
- Laboratory interval The example uses the dog interval of the Merck Veterinary Manual [15]; each laboratory sets its own.
- Flag H: above the interval. A rise of 0.3 mg/dL or more within 48 hours already counts as kidney injury, even inside the interval [9].
Unit converter
Equivalent values
- Creatinine, µmol/L–
- Creatinine, mg/L–
Conversion only changes the unit. Compare the result with the interval printed by the laboratory that measured it.
| Test | What can be found | Why it matters |
|---|---|---|
| Creatinine | Normal at first, then rising | The main kidney value; a higher creatinine on arrival was linked to more severe illness [3] |
| Urea (BUN) | High | Rises when the kidneys filter less; bleeding into the upper gut can raise it too, but not always [10] |
| SDMA | High | One of the markers IRIS lists for early kidney injury, before creatinine leaves the normal range [9] |
| Urine specific gravity | Varies | Measured on arrival in the 434-dog study (median 1.026 after ibuprofen); read with creatinine and the urine output [3, 9] |
| PCV and red cells | Low, or high | A low PCV can point to bleeding ulcers; a high PCV (51% or more) reflected dehydration and was linked to kidney injury [3] |
| Albumin | Low | Can fall with blood loss from the gut; with heavy bleeding albumin and globulins both drop [11] |
| Liver enzymes (ALT) | Sometimes high | NSAIDs can occasionally injure the liver [3]; aspirin can cause liver necrosis [1] |
| Electrolytes and blood gas | Acid–base changes | Aspirin causes breathing-related then metabolic acid–base changes; the vet corrects them [1] |
On arrival, the 225 ibuprofen dogs of the US study had a median creatinine of 1.1 mg/dL, a median BUN of 18 mg/dL and a median PCV of 50%: often normal values, which is why the vet repeats them [3].
Kidney monitoring over the following days
Kidney damage does not always show on the first blood test. The Merck Veterinary Manual advises measuring kidney values at the start and again at 24, 48 and 72 hours after aspirin poisoning, and treats ibuprofen poisoning the same way [1]. Vets grade acute kidney injury with the IRIS scale, based on blood creatinine [9]:
| IRIS grade | Blood creatinine | Ibuprofen dogs with kidney injury [3] |
|---|---|---|
| I | Below 1.6 mg/dL (below 140 µmol/L), with a rise of 0.3 mg/dL or more within 48 hours or other signs of injury | 21% |
| II | 1.7–2.5 mg/dL (141–220 µmol/L) | 39% |
| III | 2.6–5.0 mg/dL (221–439 µmol/L) | 35% |
| IV | 5.1–10.0 mg/dL (440–880 µmol/L) | 5% |
| V | Above 10.0 mg/dL (above 880 µmol/L) | None |
IRIS notes that dogs in grades I–II may regain adequate kidney function within 2 to 5 days, while grades IV–V may die within 5 to 10 days without dialysis [9]. The vet also watches urine output: less than 1 mL per kg per hour over 6 hours is classed as reduced output [9]. For long-term kidney problems, see kidney disease in dogs.
Care and outlook
Care depends on the drug, the amount and the delay. The vet may make the dog vomit and give activated charcoal, then fluids and stomach protection [1]; in the 434-dog study, dogs whose vomiting was induced at the clinic had fewer signs later [3]. After very large amounts, some hospitals use lipid infusions, plasma exchange or blood filtering [1, 3]. There is no antidote for aspirin [1].
Most dogs recover when treated early. Survival was 99% in the 434-dog study, and 87% of the 79 dogs followed were alive a year later [3]. In 62 dogs treated with plasma exchange after large overdoses, 98% survived and 31 of the 34 rechecked had normal kidney values [8]. In the emergency-room series, 96% survived; dogs that had gone without eating for more days were more likely to die or be euthanized [7].
Related articles
Other poisonings that damage the kidneys: grapes and raisins. All the foods and substances to keep away: toxic foods for dogs and cats.
En français : ibuprofène et chien.
Questions to ask your veterinarian
- Given the drug and the amount, what is the risk for my dog’s stomach and kidneys?
- Are creatinine, urea and SDMA normal today, and when will they be rechecked?
- Does the PCV or albumin suggest bleeding from the stomach or gut?
- If there is kidney injury, which IRIS grade is it, and how much urine is my dog making?
- Which signs at home mean I should come back right away?
Get your dog’s kidney results explained.
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Frequently asked questions
How much ibuprofen is poisonous to a dog?
References report vomiting and belly pain after a single 100–125 mg/kg, kidney failure from 175–300 mg/kg and seizures above 400 mg/kg [1]; a large study used 25 mg/kg as the threshold for stomach effects [3]. But dogs vary and even small amounts may need care [5]. Call your vet or a pet poison line whatever the amount.
How long does it take for ibuprofen toxicity to show in a dog?
Ibuprofen is absorbed within 30 minutes to 3 hours [1], and vomiting is the most common sign [7]. Kidney injury can appear later, on blood tests, which is why kidney values are rechecked at 24, 48 and 72 hours [1]. Do not wait for signs: call your vet now.
What are the symptoms of an ibuprofen overdose in dogs?
Vomiting, diarrhea, vomit with blood, black tarry stools, loss of appetite and belly pain; then weakness and pale gums if there is bleeding; changes in thirst and urine if the kidneys are hit; and, after large amounts, wobbling, seizures or coma [1, 12, 13].
Can a dog recover from taking ibuprofen?
Yes, most do when treated early. In a study of 434 dogs with NSAID poisoning, 99% survived [3]. The delay before treatment matters: the longer it is, the higher the risk of ulcers and kidney failure [5].
Can I give my dog ibuprofen for pain?
No. Give only medicines prescribed by your vet for your dog, and never a human painkiller without the vet. Ibuprofen is no longer recommended in dogs [1], and human doses cannot be safely converted for another species [2]. Owners who give a human NSAID often do not realize the mistake until signs appear [1].
Sources
- Hovda T. Toxicoses From Human Analgesics in Animals. Merck Veterinary Manual, reviewed 2024, updated 2025. merckvetmanual.com/toxicology/toxicoses-from-human-analgesics/toxicoses-from-human-analgesics-in-animals
- Edwards SH. Nonsteroidal Anti-inflammatory Drugs in Animals. Merck Veterinary Manual, reviewed 2021, updated 2024. merckvetmanual.com/pharmacology/inflammation/nonsteroidal-anti-inflammatory-drugs-in-animals
- Chalifoux NV et al. Outcomes of 434 dogs with non-steroidal anti-inflammatory drug toxicosis treated with fluid therapy, lipid emulsion, or therapeutic plasma exchange. J Vet Intern Med. 2023;37(1):161-172. doi.org/10.1111/jvim.16603
- Khan SA, McLean MK. Toxicology of frequently encountered nonsteroidal anti-inflammatory drugs in dogs and cats. Vet Clin North Am Small Anim Pract. 2012;42(2):289-306. doi.org/10.1016/j.cvsm.2012.01.003
- Poortinga EW, Hungerford LL. A case-control study of acute ibuprofen toxicity in dogs. Prev Vet Med. 1998;35(2):115-124. doi.org/10.1016/s0167-5877(98)00051-8
- Villar D, Buck WB, Gonzalez JM. Ibuprofen, aspirin and acetaminophen toxicosis and treatment in dogs and cats. Vet Hum Toxicol. 1998;40(3):156-162. pubmed.ncbi.nlm.nih.gov/9610496
- Steele C, Stefanovski D, Rondeau MP. Clinical outcomes and prognostic factors associated with nonsteroidal anti-inflammatory drug overdose in dogs presented to an emergency room. J Vet Emerg Crit Care. 2021;31(5):638-646. doi.org/10.1111/vec.13096
- Butty EM et al. Outcomes of nonsteroidal anti-inflammatory drug toxicosis treated with therapeutic plasma exchange in 62 dogs. J Vet Intern Med. 2022;36(5):1641-1647. doi.org/10.1111/jvim.16507
- International Renal Interest Society (IRIS). Grading of Acute Kidney Injury. 2026. iris-kidney.com/s/IRIS-AKI-Grading_2026.pdf
- eClinPath, Cornell University College of Veterinary Medicine. Urea nitrogen. eclinpath.com/chemistry/kidney/urea-nitrogen
- eClinPath, Cornell University College of Veterinary Medicine. Albumin. eclinpath.com/chemistry/proteins/albumin
- Pet Poison Helpline. Ibuprofen. petpoisonhelpline.com/poison/ibuprofen
- Pet Poison Helpline. Naproxen. petpoisonhelpline.com/poison/naproxen
- Gilmour MA, Walshaw R. Naproxen-induced toxicosis in a dog. J Am Vet Med Assoc. 1987;191(11):1431-1432. pubmed.ncbi.nlm.nih.gov/3692986
- Merck Veterinary Manual. Serum biochemical analysis reference ranges. merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/serum-biochemical-analysis-reference-ranges
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.