Pet Medication Dosage Calculator
Calculate common OTC medication dosages for dogs by body weight.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Enter your dog's weight, select the medication, and the calculator shows the standard dosage along with frequency and safety notes. Always confirm with your veterinarian before administering any medication.
- Enter dog weight. Use current body weight in pounds or kilograms. Accurate weight is essential since most dosages are weight-based.
- Select the medication. The calculator covers five common OTC medications used for dogs. Each has specific indications and contraindications listed in the safety notes.
- Read the result. The dose, frequency, and maximum are displayed. Review all safety warnings before administering.
This tool is for informational reference. It does not replace a veterinary consultation. Dogs with known health conditions, dogs on other medications, pregnant dogs, and very young puppies may have different needs or contraindications.
About Common OTC Pet Medications
Several human over-the-counter medications are used for dogs under veterinary guidance. Diphenhydramine (Benadryl) is commonly used for allergic reactions, bug stings, and mild anxiety during travel. Melatonin helps with anxiety, noise phobias, and sleep regulation. Pepto-Bismol can relieve mild gastrointestinal upset. Hydrogen peroxide is only used to induce vomiting and should only be given under direct veterinary instruction. Aspirin can address mild pain and inflammation but carries significant risks including gastrointestinal ulcers and should never be used long-term without veterinary oversight.
Never give cats medications calculated for dogs. Many dog-safe medications are toxic to cats, including aspirin, Pepto-Bismol, and many topical treatments. Always verify species-specific safety.
Frequently Asked Questions
How much Benadryl can I give my dog?
The standard dose is 1 mg of diphenhydramine per pound of body weight, given every 8-12 hours, with a maximum of 50 mg per dose. A 20-pound dog would receive 20 mg, which is one standard 25 mg tablet cut in half, or use liquid children's Benadryl at the appropriate concentration. Use only plain diphenhydramine; avoid products that combine it with decongestants like pseudoephedrine, which can be toxic to dogs. Consult your vet before use if your dog has glaucoma, prostate disease, or heart conditions.
Can I give my dog melatonin?
Melatonin is generally considered safe for dogs and is used for anxiety, noise phobias (thunderstorms, fireworks), and sleep disorders. The dose is typically 1 mg for dogs under 25 lbs, 3 mg for dogs 25-100 lbs, and 6 mg for dogs over 100 lbs. The most important caution is to check the ingredient label carefully. Some melatonin products contain xylitol, a sugar alcohol that is highly toxic to dogs and can cause life-threatening hypoglycemia. Use only plain melatonin without additional ingredients.
Can I give my dog Pepto-Bismol?
Pepto-Bismol can be given to dogs at 1 teaspoon per 10 pounds every 6-8 hours for mild stomach upset. However, it is not appropriate for all dogs. It contains bismuth subsalicylate, which is a salicylate similar to aspirin. Do not give it to dogs that are on aspirin or NSAIDs, dogs with bleeding disorders, or pregnant dogs. It can darken stools, which is normal. Never give Pepto-Bismol to cats, as salicylates can be fatal in felines. For persistent GI upset lasting more than 24 hours, see your veterinarian.
When should I induce vomiting in my dog with hydrogen peroxide?
Only induce vomiting under direct instruction from a veterinarian or animal poison control specialist. Do not induce vomiting if your dog has swallowed sharp objects, caustic substances (bleach, drain cleaner), hydrocarbons (gasoline, paint thinner), or if your dog is already unconscious, having seizures, or showing severe distress. Use only 3% hydrogen peroxide, never higher concentrations. The dose is 1 teaspoon per 5 lbs with a maximum of 3 tablespoons (9 tsp). Vomiting should occur within 15 minutes; do not repeat if it does not. Call your vet immediately if it does not work.