Important medical disclaimer

This calculator is for informational purposes only. It does not replace professional veterinary advice. Always consult your veterinarian before giving any medication to your dog. Incorrect dosing can cause serious injury or death.

ASPCA Poison Control: (888) 426-4435|Pet Poison Helpline: (855) 764-7661

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Safe dosing by weight with toxic-drug warnings

Dog Medication Dosage Calculator

Safe doses by weight with safety context

Calculate reference doses for common dog medications by body weight, then check formulation safety, toxic look-alikes, breed alerts, and emergency poison-control steps before you do anything else.

My Dogs integration

Load a saved dog or enter everything manually.

Step 1: Enter your dog's weight

Use the most recent weight you have. Small weight mistakes matter more than owners expect.

Quick range slider12.5 kg / 27.6 lb

Step 2: Select medication

Search by brand or generic name, or narrow by category first.

Benadryl (Diphenhydramine HCl)

Safe OTC reference

Useful for mild allergy symptoms, insect stings, and limited short-term sedation.

Step 3: Age and health status

These flags do not replace a veterinarian, but they do change how cautious the result should sound.

Known conditions

The result combines the dose range with formulation warnings, toxic look-alike alerts, side effects, and poison-control contact steps.

Why this page is stronger

  • Built for dog owners, not just veterinary staff calculators.
  • Covers OTC references, prescription context, and toxic look-alikes together.
  • Shows safe formulations, not just dose math.
  • Highlights MDR1 breed issues, senior caution, and organ-disease flags.
  • Pairs the calculator with an emergency-response workflow.

Before you give anything

  • Check the exact active ingredient, not just the brand name on the box.
  • Avoid all multi-symptom, decongestant, or sweetened combination products.
  • Use the lowest reasonable end of the range first unless your vet says otherwise.
  • Stop and call your veterinarian if your dog is pregnant, very young, elderly, or already on other medications.

Never give these without urgent guidance

  • Tylenol / acetaminophen
  • Ibuprofen / Advil / Motrin
  • Naproxen / Aleve
  • Xylitol-containing liquids
  • Benadryl-D / Claritin-D / any '-D' formula
  • Horse or livestock ivermectin

Emergency contacts

ASPCA Poison Control: (888) 426-4435

Pet Poison Helpline: (855) 764-7661

Common dog medication doses

Complete reference chart

These reference tables exist to slow owners down, not speed them up. The right active ingredient, the right formulation, and the right context matter just as much as the raw mg-per-kg math.

Allergy & Antihistamines

Common antihistamines used for itch, hives, and mild allergic reactions.

4 references
DrugGenericDoseFrequencySafety
BenadrylDiphenhydramine HCl1-2 mg/kgEvery 8-12 hoursSafe OTC reference
ClaritinLoratadine0.2-0.5 mg/kgEvery 24 hoursSafe OTC reference
ZyrtecCetirizine0.5-1 mg/kgEvery 12-24 hoursSafe OTC reference
HydroxyzineHydroxyzine HCl1-2 mg/kgEvery 8-12 hoursRx context

Category notes

  • - Use plain antihistamine formulations only.
  • - Avoid all '-D' products because pseudoephedrine is toxic to dogs.
  • - Liquid products should be checked carefully for xylitol.

Gastrointestinal

Acid reducers and short-term upset stomach references.

5 references
DrugGenericDoseFrequencySafety
Pepcid ACFamotidine0.5-1 mg/kgEvery 12-24 hoursSafe OTC reference
Pepto-BismolBismuth subsalicylate1 ml/kgEvery 6-8 hours, max 2 daysUse with caution
Imodium A-DLoperamide0.08-0.1 mg/kgEvery 8-12 hoursUse with caution
Prilosec OTCOmeprazole0.5-1 mg/kgEvery 24 hoursSafe OTC reference
RanitidineRanitidine1-2 mg/kgEvery 8-12 hoursSafe OTC reference

Category notes

  • - Diarrhea with blood, severe lethargy, or repeated vomiting is not a home-treatment scenario.
  • - Pepto-Bismol is short-term only and should not be stacked with aspirin or other NSAIDs.
  • - Loperamide should be avoided in MDR1-sensitive breeds.

Pain Relief

A small set of short-term or prescription pain-relief references.

4 references
DrugGenericDoseFrequencySafety
Buffered AspirinAcetylsalicylic acid10 mg/kgEvery 12 hours with foodUse with caution
RimadylCarprofen2.2 mg/kgEvery 12 hoursRx context
MetacamMeloxicam0.1 mg/kgEvery 24 hoursRx context
GalliprantGrapiprant2 mg/kgEvery 24 hoursRx context

Category notes

  • - Ibuprofen, naproxen, and acetaminophen are not safe substitutes for veterinary pain control.
  • - Do not combine aspirin or prescription NSAIDs with steroids or another NSAID.
  • - Pain medications deserve extra caution in kidney disease, liver disease, or dehydration.

Parasites & Prevention

Dewormers and heartworm-prevention references that demand breed awareness.

4 references
DrugGenericDoseFrequencySafety
Heartgard-type IvermectinIvermectin6 mcg/kgMonthly heartworm-prevention range onlyRx context
InterceptorMilbemycin oxime0.5 mg/kgMonthlyRx context
Pyrantel PamoatePyrantel pamoate5 mg/kgSingle dose, then repeat only if directedSafe OTC reference
PraziquantelPraziquantel5 mg/kgSingle doseUse with caution

Category notes

  • - Do not extrapolate from livestock or horse formulations.
  • - Heartworm prevention should follow veterinary weight bands and testing guidance.
  • - MDR1-sensitive breeds need special caution with ivermectin.

Anxiety & Sedation

Mild OTC calming references and several prescription-only examples.

4 references
DrugGenericDoseFrequencySafety
MelatoninMelatonin1 mg (Under 10 kg) | 1.5 mg (10-25 kg) | 3 mg (Over 25 kg)Every 8-12 hours as neededSafe OTC reference
TrazodoneTrazodone HCl2-5 mg/kgEvery 8-24 hours depending on planRx context
SileoDexmedetomidineTopical applicationUse only exactly as prescribedRx context
ReconcileFluoxetine1-2 mg/kgEvery 24 hoursRx context

Category notes

  • - Many calming supplements contain xylitol or extra active ingredients.
  • - Prescription behavior medications can interact with each other.
  • - Same-day sedation goals and long-term anxiety treatment are different problems.

Wound Care & Topical

Topical references for minor superficial wounds and cleaning.

4 references
DrugGenericDoseFrequencySafety
NeosporinTriple antibiotic ointmentTopical applicationApply a thin layer 2-3 times dailySafe OTC reference
ChlorhexidineChlorhexidineTopical applicationClean gently up to twice dailySafe OTC reference
VetericynHypochlorous acidTopical applicationSpray 3-4 times daily as neededSafe OTC reference
Hydrogen PeroxideHydrogen peroxide 3%Topical applicationUse once only on a wound if used at allUse with caution

Category notes

  • - Topical references apply to small superficial wounds, not punctures, abscesses, or eye injuries.
  • - Prevent licking whenever possible.
  • - Hydrogen peroxide is included mainly to discourage overuse.

Medications that are toxic to dogs

Never give these to your dog

This is the highest-priority safety section on the page. If your dog has already ingested any of these products, call poison control or go to an emergency vet immediately.

Tylenol / Paracetamol

Acetaminophen

Liver failure and red blood cell damage.

Toxic dose: Toxicity can begin around 75 mg/kg and small dogs can be endangered by a single regular-strength tablet.

Common signs

  • - Vomiting
  • - Lethargy
  • - Facial swelling
  • - Brown or pale gums

Found in

  • - Tylenol
  • - Cold and flu products
  • - Combination pain medicines

Advil / Motrin / Nurofen

Ibuprofen

GI ulceration, kidney failure, and neurologic injury.

Toxic dose: Risk starts around 25 mg/kg and rises quickly from there.

Common signs

  • - Vomiting
  • - Black stool
  • - Weakness
  • - Seizures

Found in

  • - Advil
  • - Motrin
  • - Combination pain relievers

Aleve / Naprosyn

Naproxen

Severe GI ulceration and kidney failure with a long canine half-life.

Toxic dose: Even 5 mg/kg can be dangerous.

Common signs

  • - Vomiting
  • - Abdominal pain
  • - Bloody stool
  • - Collapse

Found in

  • - Aleve
  • - Naproxen tablets

Birch sugar

Xylitol

Rapid hypoglycemia and possible liver failure.

Toxic dose: As little as 0.1 g/kg can trigger dangerous hypoglycemia.

Common signs

  • - Vomiting
  • - Weakness
  • - Collapse
  • - Seizures

Found in

  • - Sugar-free gum
  • - Some liquid medications
  • - Some melatonin
  • - Some peanut butter

Sudafed / Benadryl-D / Claritin-D

Pseudoephedrine

Severe stimulant toxicity with heart and neurologic effects.

Toxic dose: Even one tablet can be dangerous to a small dog.

Common signs

  • - Rapid heart rate
  • - Panting
  • - Agitation
  • - Seizures

Found in

  • - Decongestants
  • - Any '-D' allergy formula
  • - Cold medications

5-FU / Cancer cream

Fluorouracil

Severe neurologic toxicity and rapid death after even small exposures.

Toxic dose: Tiny skin-contact or oral doses can be fatal.

Common signs

  • - Vomiting
  • - Tremors
  • - Seizures
  • - Hyperthermia

Found in

  • - Topical skin cancer creams

Treat this as an immediate emergency.

Horse paste ivermectin / Cattle ivermectin

Livestock or horse ivermectin

Massive neurologic toxicity, coma, and death.

Toxic dose: One horse-paste syringe can be lethal to many dogs.

Common signs

  • - Ataxia
  • - Blindness
  • - Severe lethargy
  • - Coma

Found in

  • - Livestock dewormers
  • - Horse paste tubes

Emergency contacts

ASPCA Poison Control: (888) 426-4435

Pet Poison Helpline: (855) 764-7661

Or go to the nearest emergency veterinarian immediately.

How doses are calculated

The core formula

Dose = weight (kg) x dose rate

Volume = dose in mg divided by concentration in mg/ml.

Example: Famotidine for a 12.5 kg dog at 0.5 mg/kg = 6.25 mg per dose.

Why weight matters

Dogs range from roughly 1 kg toy breeds to giant breeds pushing 80 to 90 kg. A flat adult human dose can be meaningless or lethal once you apply it to that size spread.

Drug distribution, metabolism, and toxicity thresholds shift with size, age, breed, organ function, and the exact product formulation. That is why this page treats formulation warnings and contraindications as part of the answer rather than extra fine print.

Some drugs are especially poor candidates for owner improvisation because dogs metabolize them very differently from humans. Acetaminophen, ibuprofen, and naproxen all sit in that category.

When to use common dog medications

Category guidance, not just formulas

Antihistamines for mild allergic reactions

Plain diphenhydramine, loratadine, or cetirizine can appear simple, but the real risk is owners grabbing the wrong formulation. Combination products, decongestants, and sweetened liquids cause more trouble than the raw dose math.

GI medications for short-term upset stomach

Famotidine, omeprazole, and short-term bismuth products are reference tools, not universal answers to vomiting or diarrhea. Puppies, seniors, bloody stool, dehydration, and repeated vomiting all justify a faster veterinary call.

Pain relief is where owners make the most dangerous substitutions

Aspirin is a caution option at best, while ibuprofen, naproxen, and acetaminophen should not be given at all. If a dog truly needs pain control, the right comparison is not human Advil versus nothing. It is home guessing versus a veterinary pain plan.

Breed and health context change the answer

MDR1-sensitive breeds, dogs with kidney or liver disease, pregnant dogs, and dogs already on other medication all require a higher safety bar. That is why this page uses warnings as part of the calculator rather than as a footnote.

How to give your dog medication

Practical administration tips

Pill in food

Use a small amount of xylitol-free peanut butter, cream cheese, canned food, or a pill-pocket style treat. A plain treat before and after the medicated one helps dogs swallow quickly without overthinking it.

Direct pilling

Open the mouth from above, place the pill as far back on the tongue as you can safely manage, close the mouth gently, and encourage a swallow with a throat rub or water chaser.

Liquid medication

Use an oral syringe into the cheek pouch and go slowly. Fast squirting straight back increases aspiration risk and makes dogs fight the next dose harder.

Topicals and ointments

Minor superficial wounds only. Clean first, apply thin layers, and prevent licking if you can. Eye injuries, punctures, bite wounds, or swelling deserve veterinary care instead of more ointment.

Drug overdose and poisoning

Emergency guide

Emergency contacts

ASPCA Animal Poison Control

(888) 426-4435

Available 24/7. Fee may apply.

Pet Poison Helpline

(855) 764-7661

Available 24/7. Fee may apply.

Go straight to emergency care if

Your dog is collapsing, seizing, struggling to breathe, or has ingested a known toxic drug.

What to tell poison control

  1. 1. Your dog's weight in kg or lb.
  2. 2. Exact medication name and strength.
  3. 3. How much was swallowed or applied.
  4. 4. When it happened.
  5. 5. Any current symptoms.
  6. 6. Age, breed, and existing health conditions.

Inducing vomiting

Only if directed

  • - Poison control or a veterinarian told you to do it.
  • - The ingestion happened within about 2 hours.
  • - Your dog is conscious, alert, and can swallow safely.

Do not induce vomiting if

  • - Your dog is unconscious, weak, or seizing.
  • - A caustic product, petroleum product, or battery was ingested.
  • - Too much time has already passed.

Hydrogen peroxide should only be used under veterinary or poison-control direction. A common emergency reference is 1 ml/kg of 3% hydrogen peroxide, with a maximum of 45 ml, but you should still seek professional guidance immediately.

Frequently asked questions

Dog medication calculator FAQ

How much Benadryl can I give my dog?

A common reference range for plain diphenhydramine is 1 to 2 mg per kg every 8 to 12 hours, with many owners starting at the low end first. Plain formulation matters. Benadryl-D, decongestant combinations, alcohol-heavy liquids, and xylitol-containing liquids are not safe substitutes.

Can I give my dog Tylenol or acetaminophen?

No. Acetaminophen is toxic to dogs and can cause liver failure and red blood cell damage. If your dog already swallowed Tylenol or a cold-and-flu product containing acetaminophen, call poison control or an emergency veterinarian immediately.

Can I give my dog ibuprofen?

No. Ibuprofen is one of the most common and dangerous owner-misuse medications in dogs. It can cause GI ulceration, kidney injury, and neurologic signs at doses far lower than many owners expect.

How much Pepcid can I give my dog?

A widely cited short-term famotidine reference is about 0.5 to 1 mg per kg every 12 to 24 hours, but plain Pepcid AC is the key. Pepcid Complete and multi-ingredient antacid products are different products and should not be treated as interchangeable.

Is aspirin safe for dogs?

Buffered aspirin may be used short term in some dogs, but it is a caution medication rather than a casual safe option. It should not be combined with other NSAIDs or steroids and is a poor substitute for a true veterinary pain plan.

Can I give my dog melatonin for anxiety?

Plain melatonin is commonly used as a simple calming aid, but the product must be checked carefully for xylitol and added sleep ingredients. Many problems come from the formulation, not the melatonin itself.

How do I calculate my dog's medication dose?

Most weight-based references follow the same formula: dose equals body weight in kilograms multiplied by the published dose rate. Liquids then require a second step, dividing the dose by the product concentration. This page handles both steps and then adds formulation safety context.

Are there breed-specific medication concerns?

Yes. Collies, Shelties, Australian Shepherds, and several related breeds may carry MDR1 sensitivity, which changes risk around drugs such as loperamide and ivermectin. Breed context matters enough that a product safe for one dog can be dangerous for another.

My dog ate my medication. What should I do?

Move quickly. Call ASPCA Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661, and have the drug name, strength, amount, time of ingestion, and your dog's weight ready. Do not induce vomiting unless a veterinarian or poison expert tells you to do it.

Can I give my dog human antibiotics?

Not casually. Some human antibiotics are also used in dogs, but dose, interval, duration, and whether the drug even fits the infection still require a veterinarian. Guessing with leftover antibiotics is a good way to miss the real diagnosis and create resistance problems.

Related tools

Keep the rest of the context accurate

References

Sources and review context

This page is designed as a safety-first reference for dog owners and should not be used as a replacement for diagnosis, emergency triage, or a veterinarian-directed treatment plan.