What This Calculator Does
This tool estimates an aspirin (acetylsalicylic acid) dose for a dog based on its body weight, using a common reference rate of about 10 mg per kilogram given every 12 hours. It accepts weight in kilograms or pounds and lets you adjust the dose rate. This is an educational estimate, not veterinary advice. Aspirin can cause serious side effects in dogs and is dangerous or fatal for cats. Always speak to your veterinarian before dosing.
How to Use It
Enter your dog's weight and choose kg or lb. The default dose rate is 10 mg/kg, which is a typical middle-of-the-range value cited for dogs; your vet may recommend a different rate. The calculator converts pounds to kilograms (\(1 \text{ lb} = 0.4536 \text{ kg}\)), multiplies by the dose rate for a single dose, and doubles it for the 24-hour total assuming every-12-hour dosing.
The Formula Explained
The core equation is $$\text{Dose (mg)} = \text{Rate (mg/kg)} \times \text{Weight (kg)}$$. With the default 10 mg/kg, a 20 kg dog would get \(10 \times 20 = 200\) mg per dose, or 400 mg per day across two doses. Buffered or enteric-coated aspirin and the exact product strength matter, so round to a practical tablet size only under veterinary guidance.
Worked Example
A 44 lb dog converts to \(44 \times 0.4536 \approx 19.96\) kg. At 10 mg/kg that is about 199.6 mg per dose, and roughly 399.2 mg per day given twice daily.
FAQ
Is aspirin safe for dogs? Only short-term and only when a vet approves it. Long-term use risks stomach ulcers and bleeding.
Can I give it to my cat? No. Cats metabolize aspirin very slowly and can be poisoned by small amounts.
How often can it be given? The common schedule is every 12 hours, but frequency and duration should be set by your veterinarian.
