Aspirin has a lot more potential to cause harm in dogs than it does in humans. Always speak to your vet before giving your dog aspirin to minimize the risk of an adverse reaction. Familiarize yourself with the following contraindications and check if your dog is taking a medicine which interacts with aspirin to keep your dog safe.

Medical Conditions

Dogs suffering from the following medical conditions are at risk of developing side effects following the use of aspirin:

Stomach ulcers, intestinal ulcers, internal bleeding, stomach lining damage, kidney problems, liver problems, vitamin K deficiency, hemophilia, anemia, Von Willebrand’s disease, low blood platelet count, any clotting issues, NSAID allergy.


These substances are known to interact with aspirin. Using any of them in conjunction with aspirin could cause a dangerous reaction:

Acetazolamide, adefovir, anisindione, apixaban, ardeparin, brinzolamide, cabozantinib, cidofovir, dalteparin, danaparoid, dasatinib, deferasirox, desirudin, dichlorphenamide, dicumarol, dorzolamide, enoxaparin, famotidine, fondaparinux, ibritumomab, ibrutinib, ibuprofen, ketorolac, leflunomide, methazolamide, methotrexate, omacetaxine, ponatinib, ramucirumab, regorafenib, rivaroxaban, sirolimus, tacrolimus, tenofovir, teriflunomide, tinzaparin, tipranavir, tositumomab, warfarin.

Aspirin should also not be given with other NSAID drugs as doing so could lead to overdose symptoms.

List of NSAIDs:

Aspirin, banamine, carprofen, cinchophen, deracoxib, etodolac, firocoxib, ketoprofen, meclofenamic acid, paracetamol, phenylbutazone (bute), tolfenamic acid, meloxicam.

I Think I’ve Given Aspirin To An Unsuitable Dog!

If you think a dog who has taken aspirin is unsuitable, call your vet immediately for advice. Many severe reactions resulting from the use of aspirin fly under-the-radar as the physical symptoms often seem innocent. Look out for the following signs that your dog is suffering a bad reaction:

  • Changes in thirst levels
  • Excessive bleeding
  • Dark or tarry stools
  • Loss of appetite
  • Vomiting
  • Diarrhea
  • Weakness
  • Collapse