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PetDosageChart

NSAID / Antiplatelet · For Dogs

Aspirin (Acetylsalicylic Acid) dosage for dogs

Onset
30-60 minutes
Duration
12 hours
Class
NSAID / Antiplatelet

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. Sourced from Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage Calculator · 01

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Dosage Chart · 02

Aspirin dosage for dogs by weight

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Weight Low Dose Standard Max Safe Frequency
5 lbs (2.3 kg) 11.5mg 23mg 34.5mg every 12 hours
10 lbs (4.5 kg) 22.5mg 45mg 67.5mg (81mg tablet) every 12 hours
15 lbs (6.8 kg) 34mg 68mg (81mg tablet) 102mg every 12 hours
20 lbs (9.1 kg) 45.5mg 91mg (81mg tablet) 136.5mg every 12 hours
25 lbs (11.3 kg) 56.5mg 113mg 169.5mg (2 × 81mg) every 12 hours
30 lbs (13.6 kg) 68mg (81mg tablet) 136mg 204mg every 12 hours
40 lbs (18.1 kg) 90.5mg (81mg tablet) 181mg (2 × 81mg) 271.5mg every 12 hours
50 lbs (22.7 kg) 113.5mg 227mg (3 × 81mg) 340.5mg (4 × 81mg) every 12 hours
60 lbs (27.2 kg) 136mg 272mg 408mg (5 × 81mg) every 12 hours
70 lbs (31.7 kg) 158.5mg (2 × 81mg) 317mg (4 × 81mg) 475.5mg (6 × 81mg) every 12 hours
80 lbs (36.3 kg) 181.5mg (2 × 81mg) 363mg 544.5mg every 12 hours
90 lbs (40.8 kg) 204mg 408mg (5 × 81mg) 612mg every 12 hours
100 lbs (45.4 kg) 227mg (3 × 81mg) 454mg 681mg every 12 hours
120 lbs (54.4 kg) 272mg 544mg 816mg (10 × 81mg) every 12 hours
150 lbs (68 kg) 340mg (4 × 81mg) 680mg 1020mg every 12 hours

Common Uses · 03

What is Aspirin (Acetylsalicylic Acid) used for in dogs?

mild pain relief inflammation fever reduction blood clot prevention

Administration · 04

How to give Aspirin to your dog

Always use buffered or enteric-coated aspirin to reduce stomach irritation. Give with food. Baby aspirin (81 mg) is often preferred for smaller dogs. Never give aspirin to cats without specific veterinary instruction, as cats metabolize salicylates very slowly.

Available Forms

tablet, buffered tablet

Give with Food?

Yes — give with food

Side Effects · 05

Side effects of Aspirin in dogs

Common side effects

stomach upset
decreased appetite
vomiting
diarrhea

Serious side effects — call your vet

  • gastrointestinal ulceration
  • bleeding disorders
  • kidney damage
  • liver toxicity

Emergency · 06

When to call the vet

Call your vet immediately if your dog shows any of these signs:

  • Vomiting or vomiting blood
  • Dark or tarry stools
  • Loss of appetite lasting more than 24 hours
  • Increased thirst or urination
  • Unusual bruising or bleeding

Related · 08

Related medications for dogs

Sources · 09

Sources & references

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Acetylsalicylic Acid.

Read more about our methodology and how we calculate dosages.

Frequently Asked · 07

Questions about this medication

Can I give my dog aspirin for pain?
Aspirin can be given to dogs for short-term pain relief, but it is not the safest NSAID choice. Veterinary-specific NSAIDs like carprofen or meloxicam are preferred for dogs because they have fewer gastrointestinal side effects. Always consult your vet before giving aspirin.
How much aspirin can I give my dog?
The typical dose is 5-10 mg per kilogram of body weight, given every 12 hours. For a 30 lb (14 kg) dog, this would be about one baby aspirin (81 mg). Always use the lowest effective dose and give with food.
Is baby aspirin safe for dogs?
Baby aspirin (81 mg) is commonly used for dogs due to its lower dose, which allows for more precise dosing in small to medium dogs. However, "safe" is relative — aspirin carries risks of GI ulceration even at low doses, so veterinary-specific NSAIDs are generally preferred.
Can I give my dog aspirin every day?
Daily aspirin use in dogs should only be done under veterinary supervision. Long-term use increases the risk of gastrointestinal ulceration, bleeding, and kidney problems. Your vet may prescribe daily low-dose aspirin for specific conditions like blood clot prevention.

Safety · 10

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