Can dogs eat aspirin?
✓ Reviewed against PDSA, Blue Cross & Animal PoisonLine guidance · Last updated: 2026-06-17
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The full picture
Aspirin (acetylsalicylic acid) was historically given to dogs for pain relief, and old advice forums still recommend 'a small dose of children's aspirin' for joint pain. This advice is outdated and unsafe. Dogs metabolise aspirin much more slowly than humans, so accumulated doses cause significant gastric lining damage, bleeding ulcers, and acute kidney injury. Even at the doses historically used (10–20 mg/kg), gastrointestinal bleeding is common. The widespread availability of safe dog-specific NSAIDs (carprofen, meloxicam, firocoxib) means there is no longer any reason to use aspirin for canine pain. UK brand names include Bayer, Bufferin, Bayer Original, DayQuil Powders, and most own-brand aspirin tablets. Combination products with codeine (Co-codaprin) carry additional risks from the codeine.
Check individual ingredient safety at 247IngredientsCheck.
If your dog has already eaten aspirin
Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 or Pet Poison Helpline on (855) 764-7661 immediately, especially if your dog has eaten more than one tablet or shows signs of vomiting blood, black or tarry stools, or unusual lethargy. Bring the packet so dose can be calculated by weight. Treatment includes inducing vomiting (if very recent), gastric protectants (sucralfate, omeprazole), IV fluids, and monitoring for bleeding.
Risks to watch for
- Stomach ulcers and gastrointestinal bleeding
- Vomiting blood ('coffee grounds' appearance)
- Black or tarry stools (melena)
- Acute kidney injury
- Liver damage at high doses
- Increased bleeding from any wound or surgery
Safe portion size
There is no safe dose without specific veterinary direction. Your vet can prescribe dog-safe NSAIDs that don't carry these risks.
Safer alternatives
- Carprofen (Rimadyl) — vet-prescribed dog-specific NSAID
- Meloxicam (Metacam) — common US veterinary anti-inflammatory
- Gabapentin or amantadine for chronic pain (vet prescription)
- Joint supplements (green-lipped mussel, glucosamine, omega-3) for long-term joint support
How does aspirin compare to other painkillers?
Ibuprofen and naproxen (Aleve) are more toxic to dogs milligram-for-milligram than aspirin, but all human NSAIDs carry the same fundamental risk: dogs metabolise them far less efficiently than humans, so GI ulceration and kidney damage can occur even at doses that seem small by human standards. There is a vet-prescribed low-dose aspirin protocol used in some dogs, but this is always vet-directed, monitored, and dosed specifically for the individual dog — it is not the same as giving a human aspirin tablet at home.
Does size or breed matter?
Toxic dose scales with body weight, so a single adult aspirin tablet is a much bigger relative dose for a small or toy breed than for a large dog. Dogs with any history of GI ulcers, kidney disease, or on other medications (including other NSAIDs or steroids) are at elevated risk regardless of size — always disclose current medications to your vet before any aspirin is considered.