Pain medication overdose in dogs and cats
Ingestion of an incorrect NSAID or an overdose is a veterinary emergency!
Why NSAID exposure is an emergency
Non-steroidal anti-inflammatory drugs (NSAIDs) are used to relieve pain and inflammation in people and animals. When the wrong product is given, too much is administered, doses are repeated too closely, or a pet accidentally eats medication, serious poisoning can occur. Dogs and cats may initially appear well, but gastrointestinal ulceration and kidney injury can develop later. Contact a veterinarian promptly after any suspected overdose or accidental exposure.
Which medications are NSAIDs?
Common human NSAIDs include:
• Ibuprofen
• Naproxen
• Diclofenac
• Aspirin
Veterinary NSAIDs include medications such as carprofen, meloxicam, firocoxib, deracoxib and robenacoxib.
A medication prescribed safely for one pet can still be toxic to another. Human NSAIDs should never be given to a dog or cat unless specifically directed by a veterinarian. Paracetamol (acetaminophen) is not an NSAID, but it can also cause severe and potentially fatal poisoning, particularly in cats.
How does NSAID toxicosis cause harm?
NSAIDs reduce the production of prostaglandins, which contribute to pain and inflammation. Some prostaglandins are also needed to protect the stomach and intestines, maintain blood flow to the kidneys and support normal platelet function. Excessive inhibition can therefore cause gastrointestinal injury, kidney injury and, with some drugs or very large exposures, neurological or liver abnormalities.
The toxic dose varies substantially between medications and species. Cats are particularly sensitive to several NSAIDs, and a single human-strength tablet may be dangerous to a small pet.
What signs might I see?
Signs may develop within hours or may be delayed for several days. They can include:
• Vomiting, drooling, nausea or reduced appetite
• Abdominal pain or restlessness
• Diarrhoea, blood in vomit, or black and tarry faeces
• Increased thirst or urination, followed by reduced urine production in severe kidney injury
• Lethargy, weakness, pale gums or collapse
• Loss of coordination, tremors, seizures or coma after very large exposures
• Yellow discolouration of the gums, skin or eyes if liver injury occurs
Do not wait for symptoms. Early treatment offers the best chance of preventing organ damage.
What should I do?
Contact a veterinarian or emergency veterinary hospital immediately. Bring the medication packet or bottle and provide the product name, tablet strength, possible number ingested and estimated time of exposure. If the medication was prescribed, also provide the dose and time of the most recent administrations.
Do not induce vomiting or give food, milk, antacids, activated charcoal or other home remedies unless specifically instructed by a veterinarian or veterinary toxicologist. Do not give another NSAID or a corticosteroid such as prednisolone, as combining these medications can greatly increase the risk of gastrointestinal injury.
How is NSAID exposure assessed?
Risk is assessed from the exact medication, dose, species, body weight, time since exposure and any existing health conditions. Blood and urine tests may be recommended to establish baseline kidney and liver function, hydration and electrolyte levels. These tests are often repeated because abnormalities can be delayed.
How is NSAID toxicosis treated?
Treatment is tailored to the drug, estimated dose and time since exposure. It may include:
• Decontamination: if ingestion was recent and it is safe to do so, medication may be given to induce vomiting.
• Activated charcoal: may be given to reduce absorption. Repeated doses are sometimes used for NSAIDs that remain in or recirculate through the gastrointestinal tract.
• Intravenous fluids: may be recommended to maintain hydration and kidney blood flow
• Gastrointestinal protection: medications may be used to reduce stomach acid, protect damaged tissue and lower the risk of ulceration.
• Monitoring: kidney values, liver values, electrolytes, red blood cell levels, urine output and clinical signs may be monitored over several days.
• Supportive care: anti-nausea medication, pain relief that is not an NSAID, nutritional support, blood transfusion or seizure control may be required in more severe cases.
• Advanced treatment: severe overdoses may occasionally be referred for treatments such as therapeutic plasma exchange or haemodialysis where available.
What is the outlook?
The prognosis is generally very good when exposure is recognised early and appropriate treatment begins before significant organ injury develops. The outlook becomes more guarded when gastrointestinal perforation, severe bleeding, acute kidney injury, reduced urine production, seizures or liver failure occur. The exact monitoring period and treatment plan depend on the medication and dose involved.
Preventing NSAID toxicosis
• Keep all human and veterinary medications in secure cupboards and out of reach of pets.
• Store flavoured veterinary tablets carefully, as some dogs will eat an entire packet.
• Give only the medication and dose prescribed for that individual pet.
• Do not combine NSAIDs or give an NSAID with a corticosteroid unless specifically directed by a veterinarian.
• Use a medication chart or reminder system to prevent accidental double dosing.
• Contact your veterinarian before giving any human pain-relief medication.
Seek veterinary advice immediately after any suspected NSAID overdose, accidental ingestion, double dose or administration of a human NSAID – even if your pet appears completely well. Prompt assessment and decontamination may prevent life-threatening complications.
Clinically reviewed and approved by Dr Giulia Agostini, Pet Emergency Senior Veterinarian and Clinical Manager, DVM MANZCVS (ECC) August 2026