Your dog is limping, or stiff, or clearly sore — and there is a bottle of ibuprofen in the bathroom cupboard. It's the same drug you'd take yourself, it's sitting right there, and the question that follows is a number question: how much?
This is one of the few times the honest answer to a dosage question is that there is no dose. Not a small one, not a careful one, not one adjusted for weight. But if you're reading this because your dog has already swallowed some, that answer is useless to you on its own — so the numbers you actually need are below, converted into tablets, by weight, from the published toxicity thresholds. Both readers are served here. The second one should skip to what to do in the next hour.
Key takeaways
- There is no canine dose, and that is a regulatory fact, not an opinion. The FDA states that "No over-the-counter NSAIDs for dogs and cats are FDA-approved," and Merck states that "Ibuprofen is not recommended for use in dogs or cats."¹²
- The toxicity ladder has four rungs. Merck documents GI signs from an acute 100–125 mg/kg, renal failure at 175–300 mg/kg, CNS effects above 400 mg/kg, and potential death above 600 mg/kg.³
- The chronic threshold is roughly twenty times lower than the acute one. With long-term dosing, toxicity has been documented "in dogs with doses as low as 5-6 mg/kg" — about half a 200 mg tablet a day for a 40 lb dog.⁴
- Getting there fast matters more than the number does. Across 434 treated dogs, overall survival was 99%, and the factors linked to worse outcomes were a longer delay before presentation and the absence of induced vomiting.⁵
What is the correct ibuprofen dosage for a dog?
There isn't one. No over-the-counter NSAID has ever been approved for dogs, so no dose has been validated for them — and both the regulator and the standard reference text say so in one line each. The FDA: "No over-the-counter NSAIDs for dogs and cats are FDA-approved."¹ The Merck Veterinary Manual: "Ibuprofen is not recommended for use in dogs or cats."²
That is a stronger statement than it looks. Merck's pharmacology chapter does acknowledge that "Ibuprofen is an arylpropionic acid derivative used in dogs as an anti-inflammatory agent" — the drug has a history in the species. It then explains why that history ended: "However, dogs are much more sensitive to the development of gastrointestinal adverse effects from ibuprofen administration than are humans," and "At therapeutic doses, adverse effects seen in dogs include vomiting, diarrhea, gastrointestinal bleeding, and renal infection."² Note the phrase at therapeutic doses. The harm isn't confined to overdoses.
The mechanism is the same one that makes the drug work in you. "NSAIDs inhibit cyclooxygenase (COX) enzymes (COX-1 and COX-2), thereby blocking the synthesis of prostaglandins," Merck's toxicology chapter explains.³ Prostaglandins do more than carry pain signals. They also maintain the stomach's mucus layer and the blood flow through the kidney. Block them hard enough in a species that clears the drug slowly, and you are not just switching off pain.
So what is the actual answer to "my dog hurts"? A prescription. The FDA lists five active ingredients with approved canine uses — carprofen, deracoxib, firocoxib, grapiprant and meloxicam — and every one of them requires a veterinarian.¹ There is exactly one human analgesic with a published canine reference range, and it comes with its own long list of caveats; we cover it separately in the aspirin dosage chart and what vets use instead. If you're not yet sure your dog is in pain at all, the signs that a dog is hurting are worth reading before anything comes out of a cupboard.
How much ibuprofen is toxic to a dog?
Merck's toxicology chapter publishes a four-rung ladder for dogs. "An acute single ingestion of 100–125 mg/kg can lead to vomiting, diarrhea, nausea, abdominal pain, and anorexia." Above that: "Renal failure may occur with doses of 175–300 mg/kg." Higher again: "CNS effects (seizures, ataxia, listlessness, coma), in addition to renal and GI signs, can occur at doses > 400 mg/kg." And at the top: "Doses > 600 mg/kg are potentially lethal in dogs."³
| Single dose | What is documented at that level in dogs | Source |
|---|---|---|
| 5–6 mg/kg (repeated, long-term) | Toxicity has been seen with long-term administration | ACVP⁴ |
| 8–16 mg/kg (daily, 30 days) | Gastric ulceration or erosions | Merck³ |
| 50 mg/kg | "Signs of toxicity may be seen" | ACVP⁴ |
| 100–125 mg/kg | Vomiting, diarrhea, nausea, abdominal pain, anorexia | Merck³ |
| 175–300 mg/kg | Renal failure may occur | Merck³ |
| Above 400 mg/kg | CNS effects — seizures, ataxia, listlessness, coma | Merck³ |
| Above 600 mg/kg | Potentially lethal | Merck³ |
One thing worth saying out loud, because almost no page that ranks for this question says it: the authorities do not agree on the bottom rung. Merck puts the first acute signs at 100–125 mg/kg. The American College of Veterinary Pharmacists puts them lower — "Signs of toxicity may be seen at doses of 50 mg/kg (22 mg/lb) in dogs."⁴ That is a two-fold difference between two entirely reputable sources, and it exists because "toxicity" is being measured against slightly different endpoints in different case series.
You do not have to resolve it. Act on the lower figure. A threshold is a place where harm has been recorded in some dogs, not a fence that keeps your dog safe below it — and your dog's age, kidneys, hydration and any other medication all move the line.
What do those thresholds mean in tablets for my dog's weight?
A standard over-the-counter ibuprofen tablet is 200 mg. Converting Merck's and the ACVP's figures into tablet counts is straightforward arithmetic, and it turns an abstract mg/kg number into the thing you can actually check against the packet in your hand.
| Dog's weight | 50 mg/kg signs may be seen | 100 mg/kg GI signs | 175 mg/kg renal failure | 400 mg/kg CNS effects | 600 mg/kg potentially lethal |
|---|---|---|---|---|---|
| 10 lb (4.5 kg) | 1.1 tablets | 2.3 | 4.0 | 9.1 | 13.6 |
| 20 lb (9.1 kg) | 2.3 tablets | 4.5 | 7.9 | 18.1 | 27.2 |
| 40 lb (18.1 kg) | 4.5 tablets | 9.1 | 15.9 | 36.3 | 54.4 |
| 60 lb (27.2 kg) | 6.8 tablets | 13.6 | 23.8 | 54.4 | 81.6 |
| 80 lb (36.3 kg) | 9.1 tablets | 18.1 | 31.8 | 72.6 | 108.9 |
Counts are our arithmetic on the published mg/kg figures, using 200 mg tablets.³⁴ Read this table as triage information for a phone call — never as permission. Nothing in it says a dose below the first column is safe, and a 10 lb dog reaching the first rung on a single ordinary tablet is exactly why the ACVP warns that "as little as one 200 mg ibuprofen tablet can toxic to cats and smaller dogs."⁴
Two practical notes before you use it. First, check the strength on the box: 200 mg is the common over-the-counter tablet, but prescription ibuprofen comes in 400, 600 and 800 mg, and a single 800 mg tablet does to a 40 lb dog what four of the small ones would. Second, liquid gel capsules and children's suspensions change the arithmetic again, so read the label rather than assuming. If you can, take the packet with you to the vet.
Why is half a tablet every day worse than one raided bottle?
Because the chronic threshold sits roughly twenty times below the acute one. The ACVP reports that "With long-term administration, toxicity has been seen in dogs with doses as low as 5-6 mg/kg (2-3 mg/lb)."⁴ For an 18 kg dog — a 40 lb spaniel — that is 90 to 109 mg a day. Half a 200 mg tablet is 100 mg. It lands in the middle of the range.
Merck's chapter records the same pattern from the other direction: "Dogs dosed with ibuprofen at 8–16 mg/kg, PO, every 24 hours, for 30 days showed gastric ulceration or erosions, along with other clinical signs of GI disturbances."³ For that same 40 lb dog, 8–16 mg/kg is 145 to 290 mg daily — around one tablet. A month of one tablet a day produced ulcers.
This is the part of the topic that worries veterinarians most, and it's the part the search results bury. The owner who panics is the one whose dog raided the bottle. The owner who quietly gives "just half a tablet for his hips, he's much better on it" has no incident to panic about, gets positive feedback because the drug genuinely does relieve pain, and accumulates injury invisibly. If stiff hips are what started this, tracking arthritis at home is the more useful place to put that effort. An ASPCA poison-control review of these drugs put it plainly: in chronic exposure to therapeutic doses of aspirin and ibuprofen, "the development of gastric ulcers and analgesic nephropathy is unpredictable."⁶ Unpredictable means you cannot watch for it.
What are the signs of ibuprofen poisoning, and when do they start?
Early and late, in two waves. The ACVP reports that signs "can be seen 2-6 hours after ingestion" — but adds that "serious complications may not be seen for 4-5 days post-ingestion."⁴ A dog who seems perfectly well the same evening has told you very little.
VCA's list of what turns up at lower doses is "decreased appetite, vomiting (sometimes with blood), diarrhea, depression, abdominal pain, dark tarry stools, pale gums, and bloody stools." At higher doses it adds "incoordination, increased or decreased drinking and urination, yellow discoloration of the skin and mucous membranes (jaundice/icterus), pale mucous membranes, agitation, tremors, seizures, and coma."⁷
| What you may see | What it points at | When |
|---|---|---|
| Vomiting, diarrhea, drooling, refusing food, abdominal pain | Stomach and gut irritation | 2–6 hours⁴ |
| Black tarry stool (melena), blood in vomit, pale gums | Gastrointestinal bleeding or ulceration | Hours to days⁴⁷ |
| Drinking or urinating noticeably more or less than usual | Kidney injury | Often 4–5 days⁴ |
| Yellowed gums or skin | Liver involvement | Days⁷ |
| Wobbliness, tremors, agitation, seizures, collapse | Central nervous system effects — a large exposure | Emergency, now⁷ |
VCA also notes that recovery isn't always complete: "In some cases, liver or kidney damage may be permanent."⁷ That is the argument against the wait-and-see approach in one sentence. The window in which decontamination helps closes long before the damage announces itself.
What should you do in the next hour?
Call, with three facts ready: your dog's weight, the tablet strength, and the largest number of tablets that could be missing. Do not wait for symptoms, and do not make your dog vomit unless a veterinary professional tells you to — hydrogen peroxide given badly causes its own injuries.
- Weigh your dog, or use the most recent weight from their vet record. Every threshold on this page is per kilogram, so without a weight none of them mean anything.
- Find the packet and read the strength. 200 mg is the usual over-the-counter tablet; 400, 600 and 800 mg tablets exist, and liquid capsules differ again.
- Count what is missing, and assume the worst plausible number rather than the most comfortable one.
- Call now — your veterinarian, the nearest emergency hospital, or the ASPCA Animal Poison Control Center on (888) 426-4435. Take the packet with you if you travel.
Then take the reassurance, because it is earned. A 2023 multicentre study in the Journal of Veterinary Internal Medicine followed 434 dogs treated for NSAID toxicosis between 2015 and 2020 and concluded that "NSAID toxicosis generally carries an excellent prognosis in dogs." Overall survival was 99%.⁵
What that paper found about why some dogs did worse is the most useful thing on this page. "Increased maximum time to presentation," a higher baseline creatinine and packed cell volume, and "absence of induced emesis" were each associated with greater clinical severity.⁵ Two of those four are about how fast you moved. The dose is fixed the moment it's swallowed; the clock is not. In a companion study of 62 dogs treated with plasma exchange, the median time between ingestion and presentation was 4 hours, with a range from 1 to 20.⁸
The same 434-dog study also found that "Ibuprofen toxicosis was associated with more severe clinical signs compared with carprofen."⁵ Carprofen is a licensed veterinary NSAID. Even among NSAID overdoses, the human drug was the rougher one.
So: ASPCA Animal Poison Control Center, (888) 426-4435 — available "24/7, 365 days a year," and the ASPCA notes that "A one-time consultation fee can help you avoid thousands in potential emergency vet costs."⁹ Your own veterinarian or the nearest emergency hospital is the other call, and either is better than neither. Bring the packet.
Is ibuprofen even worse for cats?
Yes, by roughly a factor of two. Merck states that "Cats are susceptible to ibuprofen toxicosis at approximately half the dose required to cause toxicosis in dogs," and explains why: "Cats are especially susceptible because they have limited glucuronide conjugating capacity."³ Glucuronidation is a main route for clearing the drug, and cats have less of it.
The ACVP's figure for cats is 25 mg/kg against 50 mg/kg in dogs.⁴ A 10 lb cat is about 4.5 kg, so a single 200 mg tablet delivers roughly 44 mg/kg — well past it. The FDA makes the same point from the metabolic side: "Compared to other species, cats may have a reduced ability to break down NSAIDs," and only two NSAIDs are approved for cats at all, meloxicam and robenacoxib, with none approved for long-term feline use.¹ For a cat, one dropped tablet found and eaten is a call to make immediately.
How do you make sure this never happens again?
Two fixes, because there are two different failures here. The raided bottle is a storage problem: human medication belongs behind a door a dog cannot open, and a handbag on the floor is the classic route. The daily half-tablet is a communication problem, and it's much harder to see.
Human medicines are uniquely exposed to that second failure because they arrive without a schedule attached. A prescription comes with a label, a frequency and a finish date. A cupboard painkiller comes with a household habit, and a habit is easy to start and almost impossible to audit. Nobody logs it, because it doesn't feel like medication. It feels like helping.
The countermeasure is the same one that works for preventing an accidental double dose: one shared record, a name and timestamp on every entry, and the product and strength written down rather than the drug's nickname. "Gave him something for his hip" is the sentence that hides both the drug and the amount. It's the same gap behind most missed and duplicated doses in multi-person households, and it's worth closing before there's an incident to explain. If your dog is on a prescribed veterinary NSAID instead, the risk shifts to doubling it — which we cover in what to do after two doses of Metacam.
Veterinary medical disclaimer: SteadyTails is a logging and coordination tool, not a substitute for veterinary care. Nothing here is a dosing instruction, and no part of this article should be read as describing a safe amount of ibuprofen for a dog or a cat — there is no approved veterinary dose of this drug for either species. The thresholds quoted are published toxicology reference figures, and the tablet counts derived from them are arithmetic offered to help you describe an exposure accurately over the phone, not to help you decide whether one is needed. If your dog or cat has swallowed ibuprofen in any amount, contact your veterinarian or an emergency animal hospital immediately, and do not induce vomiting unless a veterinary professional instructs you to. The ASPCA Animal Poison Control Center is available on (888) 426-4435, 24/7, 365 days a year; a one-time consultation fee applies.⁹
"How much did he actually get, and when?"
Those are the first two questions the poison-control line asks, and reconstructing them from memory at midnight is how people lose the hour that matters. SteadyTails keeps every dose — prescription or cupboard, given or refused — on one timeline the whole household can see, with the product, the strength, the person and the time on each entry. Coming soon to iOS and Android.
Join the SteadyTails waitlist →References
- U.S. Food and Drug Administration. Get the Facts about Pain Relievers for Pets — "No over-the-counter NSAIDs for dogs and cats are FDA-approved." An NSAID marketed for dogs or cats without a prescription is "an unapproved animal drug, meaning FDA has not reviewed information about the drug." On cats: "Compared to other species, cats may have a reduced ability to break down NSAIDs"; "Only two NSAIDs are FDA-approved for cats: meloxicam (sold under several brand and generic names) and robenacoxib (sold under the brand name ONSIOR)"; "Currently, no NSAIDs are approved for long-term use in cats." Active ingredients with FDA-approved uses in dogs, as listed: carprofen, deracoxib, firocoxib, grapiprant and meloxicam. Content current as of 09/29/2022. fda.gov Retrieved 2026-09-22.
- Merck Veterinary Manual. Nonsteroidal Anti-inflammatory Drugs in Animals (Pharmacology) — "Ibuprofen is an arylpropionic acid derivative used in dogs as an anti-inflammatory agent." "However, dogs are much more sensitive to the development of gastrointestinal adverse effects from ibuprofen administration than are humans." "At therapeutic doses, adverse effects seen in dogs include vomiting, diarrhea, gastrointestinal bleeding, and renal infection." "Ibuprofen is not recommended for use in dogs or cats." merckvetmanual.com Retrieved 2026-09-22.
- Merck Veterinary Manual. Toxicoses From Human Analgesics in Animals (Toxicology) — mechanism: "NSAIDs inhibit cyclooxygenase (COX) enzymes (COX-1 and COX-2), thereby blocking the synthesis of prostaglandins." Chronic dosing: "Dogs dosed with ibuprofen at 8–16 mg/kg, PO, every 24 hours, for 30 days showed gastric ulceration or erosions." Acute ladder: "An acute single ingestion of 100–125 mg/kg can lead to vomiting, diarrhea, nausea, abdominal pain, and anorexia"; "Renal failure may occur with doses of 175–300 mg/kg"; "CNS effects (seizures, ataxia, listlessness, coma), in addition to renal and GI signs, can occur at doses > 400 mg/kg"; "Doses > 600 mg/kg are potentially lethal in dogs." Cats: "Cats are susceptible to ibuprofen toxicosis at approximately half the dose required to cause toxicosis in dogs" and "Cats are especially susceptible because they have limited glucuronide conjugating capacity." merckvetmanual.com Retrieved 2026-09-22.
- American College of Veterinary Pharmacists. Ibuprofen & Naproxen (Pet Poison Control List) — "Signs of toxicity may be seen at doses of 50 mg/kg (22 mg/lb) in dogs" and "25 mg/kg (11 mg/lb) in cats." "With long-term administration, toxicity has been seen in dogs with doses as low as 5-6 mg/kg (2-3 mg/lb)." "As little as one 200 mg ibuprofen tablet can toxic to cats and smaller dogs" [quoted as printed]. Signs: "Loss of appetite or refusal to eat, abdominal pain, vomiting, diarrhea, increased production of saliva, and melena (black, tarry stool)." Timing: "Signs of toxicity (particularly gastrointestinal symptoms) can be seen 2-6 hours after ingestion. However, serious complications may not be seen for 4-5 days post-ingestion." vetmeds.org Retrieved 2026-09-22.
- Chalifoux NV, Butty EM, Mauro KD, Moyle RB, Ehrhardt CM, Robertson JB, Labato MA, Culler CA, Londoño LA, Vigani A, Ueda Y, Suter SE, Lynch AM. 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 Jan;37(1):161-172. doi:10.1111/jvim.16603 — "Four hundred thirty-four dogs with NSAID intoxications (2015-2020)." "Increased maximum time to presentation (P < .001), higher baseline creatinine (P < .001) and PCV (P = .007), and absence of induced emesis (P < .001) were associated with greater clinical severity." "Ibuprofen toxicosis was associated with more severe clinical signs compared with carprofen (P = .03)." "Overall survival rate was 99%." Conclusion: "NSAID toxicosis generally carries an excellent prognosis in dogs." Abstract verified via NCBI E-utilities. pubmed.ncbi.nlm.nih.gov Retrieved 2026-09-22.
- Villar D, Buck WB, Gonzalez JM. Ibuprofen, aspirin and acetaminophen toxicosis and treatment in dogs and cats. Vet Hum Toxicol. 1998 Jun;40(3):156-62 — from the ASPCA National Animal Poison Control Center: "Whereas in acute exposure, where the clinical course of an overdose to all 3 drugs is predictable in relation to the amount ingested, in chronic exposure to therapeutic doses of aspirin and ibuprofen, the development of gastric ulcers and analgesic nephropathy is unpredictable." "Ibuprofen is not recommended for prolonged treatment in dogs and cats due to the likelihood of ulcer formation." "Following acute ingestion of aspirin or ibuprofen, treatment is essentially symptomatic and supportive following early decontamination procedures." Abstract verified via NCBI E-utilities. pubmed.ncbi.nlm.nih.gov Retrieved 2026-09-22.
- VCA Animal Hospitals. Ibuprofen Poisoning in Dogs — lower-dose signs: "decreased appetite, vomiting (sometimes with blood), diarrhea, depression, abdominal pain, dark tarry stools, pale gums, and bloody stools." Higher-dose signs: "incoordination, increased or decreased drinking and urination, yellow discoloration of the skin and mucous membranes (jaundice/icterus), pale mucous membranes, agitation, tremors, seizures, and coma." On prostaglandins: "these mediators are also important in maintaining normal gastrointestinal, kidney, liver, and blood clotting functions." Treatment: "Early decontamination and treatment are key." Prognosis: "In some cases, liver or kidney damage may be permanent." Page last updated Aug 14, 2026. vcahospitals.com Retrieved 2026-09-22.
- Butty EM, Suter SE, Chalifoux NV, Lynch AM, Mauro KD, Moyle RB, Ehrhardt CM, Robertson JB, Culler CA, Londoño LA, Vigani A, Ueda Y, Labato MA. Outcomes of nonsteroidal anti-inflammatory drug toxicosis treated with therapeutic plasma exchange in 62 dogs. J Vet Intern Med. 2022 Sep;36(5):1641-1647. doi:10.1111/jvim.16507 — "The median dose of ibuprofen, carprofen or naproxen ingested was 533 mg/kg (range, 36-4857 mg/kg), 217 mg/kg (range, 88-625 mg/kg) and 138 mg/kg (range, 26-3000 mg/kg), respectively." "The median time between ingestion and presentation was 4 hours (range, 1-20 hours)." "Sixty-one (98.4%) dogs survived to discharge, and none were rehospitalized." Abstract verified via NCBI E-utilities. pubmed.ncbi.nlm.nih.gov Retrieved 2026-09-22.
- ASPCA Animal Poison Control Center. Animal Poison Control — the centre's number is given as "(888) 426-4435"; "We are available 24/7, 365 days a year, so you can get expert guidance the moment a poisoning concern arises"; "A one-time consultation fee can help you avoid thousands in potential emergency vet costs." aspca.org Retrieved 2026-09-22.