Aspirin for Dogs: Risks and Toxicity Calculator
Vets sometimes prescribe aspirin for specific conditions, but for everyday pain most now prefer NSAIDs made for dogs, which carry less risk of stomach bleeding. Aspirin cannot be combined with other NSAIDs or steroids and must be stopped before surgery. We do not calculate a home dose.
This page does not calculate a dose to give. Enter your pet's weight and what they swallowed to estimate the exposure for your vet or a poison line.
Cats clear aspirin very slowly (for days), so this calculator uses one-fifth of the dog thresholds for cats. Any aspirin exposure in a cat needs a vet call.
If your pet swallowed aspirin, this estimates the mg/kg. Published guidance lists stomach ulceration from about 50 mg/kg in dogs, more serious toxicity above about 100 mg/kg and neurological signs above about 450 mg/kg. Cats clear aspirin very slowly and are far more sensitive.
Warnings before giving Aspirin
- Never combine aspirin with a prescribed dog NSAID (carprofen, meloxicam, etc.) or steroids: the ulcer risk multiplies.
- Signs: vomiting, black stool, not eating, fast breathing, weakness.
- Coated or "safety" aspirin can pass through undigested, so it is less predictable.
Cats clear aspirin very slowly (for days), so this calculator uses one-fifth of the dog thresholds for cats. Any aspirin exposure in a cat needs a vet call.
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Questions owners ask
Can I give my dog baby aspirin?
Only if your vet tells you to and gives you a dose. Many vets now prefer dog-specific NSAIDs, and aspirin can't be mixed with those or with steroids.
How much aspirin is toxic to a dog?
Published guidance lists stomach ulceration from about 50 mg/kg, more serious effects above about 100 mg/kg and neurological signs above about 450 mg/kg. A 10 lb (4.5 kg) dog reaches 50 mg/kg with less than one regular 325 mg tablet.