Pet Education
Pet Education Pet Education Pet Education

Learn about Vetco
Free Shipping on orders over $49
Aspirin (Acetylsalicylic Acid)
Veterinary & Aquatic Services Department, Drs. Foster & Smith
Pain Relief
Print Article | Email Article
Bookmark and Share
Click here for a pdf version of this article. 


Aspirin is used to treat pain, inflammation and fever in dogs. Aspirin can be fatal in cats; use it only under direct supervision of your veterinarian. Contact your veterinarian if your pet experiences depression, vomiting, bloody or black stools, increased respiration or weakness while taking aspirin.

Generic Name
Acetylsalicylic Acid/Aspirin

Brand Names
Ascriptin, Bayer, Bufferin

Type of Drug
Non-steroidal anti-inflammatory (NSAID), pain reliever, fever reducer

Form and Storage
Store at room temperature protected from moisture.

Indications for Use
Treatment of pain, inflammation, fever.

General Information
Not FDA approved for use in veterinary medicine, but it is a common and accepted practice to use aspirin in dogs. Available over the counter. Used in dogs for pain relief from overused muscles or arthritis and joint disease, including hip dysplasia.

Duration of treatment depends on response to treatment and reason for treatment. Give with a small amount of food to decrease the risk of ulcers forming.

Aspirin can be fatal to cats. Aspirin should NOT be given to cats except under direct supervision by your veterinarian.

Side Effects
May see lack of appetite, vomiting, or black or bloody stool which may be symptoms of stomach ulcers. May cause kidney damage. Symptoms include lack of appetite, vomiting, or an increase or decrease in water consumption. Less commonly seen are allergic reactions, anemia, or low blood protein levels due to blood loss.

Do not use in patients hypersensitive (allergic) to it.

Only use under direct supervision of a veterinarian in cats, as they metabolize it very slowly (over 3-4 days). Death may occur with use in cats.

Do not use aspirin products that contain other ingredients such as caffeine, codeine, or acetaminophen. These drugs can kill animals.

Stop aspirin treatment at least 1 week prior to surgery to help avoid bleeding problems during or after surgery.

Do not use in dogs who have bleeding problems such as von Willebrand's Disease or who have stomach ulcers.

Not for use in animals that have asthma or kidney disease.

Not for use in pregnant or lactating animals.

May cause false positive or negative urine glucose test results.

Use buffered aspirin, not enteric-coated aspirin (the coating can decrease the absorption of aspirin from the intestines in dogs).

Drug or Food Interactions
Do not use with other anti-inflammatories like corticosteroids or other NSAIDs such as Rimadyl or EtoGesic.

Toxic effects are more likely if used with urinary acidifiers such as methionine or high doses of Vitamin C.

Furosemide may increase blood levels of aspirin.

Phenobarbital and corticosteroids may decrease the effect of aspirin.

Heparin or warfarin given with aspirin may increase risk of bleeding.

Aspirin may increase the blood levels of digoxin (a heart medication), methotrexate, valproic acid, phenytoin, warfarin, penicillins, and sulfonamides.

Use with aminoglycoside antibiotics increases the risk of kidney disease.

The antacids in buffered aspirin may alter tetracycline products, allow at least 1 hour between giving them if need to treat with both.

Give with a small amount of food to decrease the risk of ulcers forming.

May see depression, vomiting with or without blood in it, blood in the stool, black (from digested blood) stool, lack of appetite, increased body temperature, increased rate of breathing, weakness, fluid buildup in lungs or brain, changes in the potassium and sodium levels in the blood, incoordination, seizures, coma, or death.

Keep this and all other medications out of the reach of children and pets.

If you think your pet has been poisoned...

Contact your veterinarian or one of the Animal Poison Hotlines (listed below) if you think your pet may have accidentally received or been given an overdose of the medication.

**ASPCA Animal Poison Control Center - 24-hour service available throughout North America.

1-888-4ANI-HELP (1-888-426-4435). $65.00 per case, billed to caller's credit card.

Follow-up calls can be made for no additional charge by dialing 888-299-2973.

There is no charge when the call involves a product covered by the Animal Product Safety Service.

**Pet Poison Helpline - 24-hour service available throughout North America for pet owners and veterinary professionals who require assistance with treating a potentially poisoned pet.

1-800-213-6680 ($59.00 per incident). Staffed 24-hours a day.

Updated 6/20/17

Click here for a pdf version of this article. 
Print Article | Email Article