CONDITION
Ibuprofen Toxicity
Ibuprofen toxicity occurs when a dog or cat is exposed to ibuprofen—a common pain relief medicine found in many households—in an amount that overwhelms the body's ability to process it safely. Ibuprofen belongs to a class of drugs that can interfere with protective mechanisms in the stomach lining and kidneys, and in larger exposures may affect the nervous system. Even doses that are safe for humans can be harmful to pets, particularly cats, who metabolise the drug much more slowly. Owners often arrive on this page after discovering their pet has swallowed ibuprofen tablets, or because they have noticed signs such as vomiting, reduced appetite, abdominal discomfort, or changes in behaviour hours to days after a possible exposure. The time between ingestion and the appearance of signs can vary, and some animals may appear well initially. This page explores the signs that may suggest ibuprofen toxicity, the mechanisms by which ibuprofen affects the body, the investigations that help clarify the nature and severity of exposure, and the approaches used to manage the condition and support recovery.
Why this matters now
Ibuprofen toxicity typically arises as an unplanned event rather than being linked to any particular age, breed, or life stage. Exposure often occurs when a pet gains access to a handbag, bedside table, or bathroom cabinet where tablets are stored, or when an owner administers ibuprofen in the belief it may relieve pain or fever. Dogs are involved more frequently than cats, largely because they tend to investigate and consume items more readily, though cats who are exposed may show signs at lower doses due to slower drug clearance.
The appearance and evolution of signs can vary considerably depending on the amount ingested and the individual animal's ability to metabolise the drug. Gastrointestinal signs such as vomiting or reduced appetite may emerge within hours, whilst changes linked to kidney function or the nervous system may take one to several days to become apparent. Some animals remain quiet and show subtle changes in behaviour before more obvious signs develop, and the severity can range from mild stomach upset to multi-organ involvement.
Signals & patterns
Early signals
Vomiting within hours
Vomiting may begin a few hours after ingestion and can occur once or repeatedly. The material brought up may contain food, fluid, or in some cases evidence of tablet fragments or blood-tinged streaks if the stomach lining has been irritated.
Reduced appetite or refusal of food
A dog or cat may show less interest in meals or turn away from food entirely. This often reflects nausea or discomfort in the upper digestive tract, and the change may be noticed before vomiting begins.
Quieter than usual or withdrawn
An animal may spend more time resting, seek out quiet corners, or show less enthusiasm for interaction. This shift in demeanour can accompany abdominal discomfort or a general sense of malaise.
Abdominal discomfort or guarding
An owner may notice their pet tenses when the belly is touched, adopts a hunched posture, or becomes restless and reluctant to settle. These behaviours can reflect irritation or inflammation in the stomach lining.
Increased thirst or urination
Some animals begin drinking more water and producing larger volumes of urine in the hours to days following exposure. This pattern may indicate early changes in kidney function as the organ attempts to clear the drug and manage fluid balance.
Later signals
Dark or tar-like stools
Stools that appear black, sticky, or tar-like often reflect digested blood from bleeding in the stomach or upper small intestine. This change typically takes at least a day to develop and suggests more significant damage to the gastrointestinal lining.
Pale gums or weakness
Gums that look paler than usual, along with lethargy or unsteadiness, may indicate anaemia from gastrointestinal blood loss or changes in circulation. These signs tend to emerge when the condition has progressed or the dose ingested was substantial.
Tremors or incoordination
In cases of larger exposures, an animal may develop muscle tremors, appear unsteady on their feet, or show other changes in movement or responsiveness. These neurological signs suggest the drug has reached concentrations that affect the nervous system.
Reduced or absent urine output
An owner may notice their pet is urinating much less frequently or producing very small amounts of urine. This pattern can indicate acute kidney injury and typically becomes apparent one to several days after ingestion.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
Last reviewed: Invalid Date ·