Antibiotic (Penicillin) · For Dogs

Amoxicillin dosage reference for dogs (Amoxil)

This page's standard weight-based reference is 10 mg per kg (4.54 mg per lb), with every 8-12 hours recorded as the reference frequency. Use the calculator to see the arithmetic for your dog's weight, then confirm the indication, product, and actual dose with a veterinarian.

Onset: 1-2 hours
Duration: 8-12 hours
Class: Antibiotic (Penicillin)

Weight-based calculator estimate from the references listed on this page. This page has not been independently DVM-reviewed — see our methodology .

This information is for educational purposes only. Always consult your veterinarian before giving medication to your pet. Do not use this calculator for emergencies, overdoses, pregnancy, very young animals, very old animals, pets with liver/kidney disease, or pets taking multiple medications.

Each medication page lists the references recorded for its data. The calculator math and editorial presentation are maintained by PetDosageChart; a page is independently DVM-reviewed only when a named reviewer byline appears. See our methodology and limitations.

Amoxicillin (often known by brand names such as Amoxil and Clavamox (with clavulanate)) is an antibiotic (penicillin) commonly used in veterinary medicine for bacterial infections, skin infections, urinary tract infections, respiratory infections, and dental infections. Understanding the correct dosage, administration, and potential side effects of Amoxicillin is critical for your dog’s safety and well-being.

A typical Amoxicillin dose for dogs is around 10 mg/kg every 8-12 hours, within a usual range of 5-25 mg/kg. Available forms include tablet, capsule, and liquid suspension.

Calculator Warning: Use this only as an educational estimate. Your veterinarian may prescribe a different dose based on your pet’s condition, age, weight, other medications, and medical history.

Amoxicillin Dosage Calculator for Dogs

Enter your dog’s weight below to estimate the Amoxicillin dose from the 10 mg/kg guideline. Your veterinarian may adjust it for your dog’s age, condition, and other medications, so treat the result as an educational starting point, not a prescription.

Dosage Calculator · 01

Enter your dog's weight

Quick Dosage Chart

Typical Amoxicillin amounts for common dog weights, for quick reference:

Dosage Chart · 02

Amoxil weight-based reference chart for dogs

Scroll sideways to see full table

Weight	Lower Reference	Standard Reference	Upper Reference	Frequency
5 lbs (2.3 kg)	11.5 mg	23.0 mg	57.5 mg (50mg tablet)	every 8-12 hours
10 lbs (4.5 kg)	22.5 mg	45.0 mg (50mg tablet)	112.5 mg	every 8-12 hours
15 lbs (6.8 kg)	34.0 mg	68.0 mg	170.0 mg	every 8-12 hours
20 lbs (9.1 kg)	45.5 mg (50mg tablet)	91.0 mg (2 × 50mg)	227.5 mg	every 8-12 hours
25 lbs (11.3 kg)	56.5 mg (50mg tablet)	113.0 mg	282.5 mg	every 8-12 hours
30 lbs (13.6 kg)	68.0 mg	136.0 mg	340.0 mg (7 × 50mg)	every 8-12 hours
40 lbs (18.1 kg)	90.5 mg (2 × 50mg)	181.0 mg	452.5 mg (9 × 50mg)	every 8-12 hours
50 lbs (22.7 kg)	113.5 mg	227.0 mg	567.5 mg	every 8-12 hours
60 lbs (27.2 kg)	136.0 mg	272.0 mg	680.0 mg	every 8-12 hours
70 lbs (31.7 kg)	158.5 mg (3 × 50mg)	317.0 mg	792.5 mg (16 × 50mg)	every 8-12 hours
80 lbs (36.3 kg)	181.5 mg	363.0 mg	907.5 mg (18 × 50mg)	every 8-12 hours
90 lbs (40.8 kg)	204.0 mg (4 × 50mg)	408.0 mg (8 × 50mg)	1020.0 mg	every 8-12 hours
100 lbs (45.4 kg)	227.0 mg	454.0 mg (9 × 50mg)	1135.0 mg	every 8-12 hours
120 lbs (54.4 kg)	272.0 mg	544.0 mg (11 × 50mg)	1360.0 mg (27 × 50mg)	every 8-12 hours
150 lbs (68 kg)	340.0 mg (7 × 50mg)	680.0 mg	1700.0 mg (34 × 50mg)	every 8-12 hours

Parenthetical tablet amounts are arithmetic comparisons only. They do not account for scoring, release type, concentration, product labeling, or whether this medication is appropriate for an individual animal.

By Weight

Amoxil reference by dog weight

Choose a common weight to open its optional reference page. Use the main medication calculator for a different exact weight.

Common-weight pages are convenience views of the same educational reference, not separate medical recommendations.

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How to Give Amoxicillin to Your Dog

Amoxicillin can be given with or without food, but giving with food may reduce stomach upset. Always complete the full course of antibiotics as prescribed, even if your dog appears to feel better before the medication is finished. Stopping early can lead to antibiotic resistance.

It is generally recommended to give Amoxicillin with food to help reduce stomach upset. It may interact with methotrexate, anticoagulants, bacteriostatic antibiotics (may reduce effectiveness), and allopurinol.

Side Effects and Safety

Common side effects include diarrhea, nausea, vomiting, and decreased appetite. More serious side effects can occur, such as allergic reaction (facial swelling, hives), severe diarrhea, difficulty breathing, and seizures (rare, at very high doses).

Cautions · 12

When Amoxil should be used with caution or avoided

Some dogs should not take Amoxil, or need a different dose and closer monitoring. Tell your veterinarian about your pet's full health history and every other medication or supplement they take before giving Amoxil.

known penicillin allergy
known hypersensitivity
certain antibiotic-resistant infections

Interactions · 13

Amoxil drug interactions

Amoxil can interact with other drugs. This list is not complete — always give your veterinarian a full list of your dog's medications and supplements.

methotrexate

anticoagulants

bacteriostatic antibiotics (may reduce effectiveness)

allopurinol

Calculator Limits · 14

When not to use this calculator

This calculator gives a general educational estimate for a healthy adult dog at a known weight. Do not rely on it in these situations — talk to your veterinarian instead:

In an emergency, or after accidental ingestion or a suspected overdose
For pregnant or nursing pets
For very young or very old dogs
For pets with liver disease, kidney disease, or another chronic illness
For pets taking several medications at once
When you are not sure of your dog's current, accurate weight
For combination products that contain additional active ingredients

Overdose · 15

Suspected overdose: what to do

If you think your dog had too much Amoxil, or swallowed any medication by accident, act right away. Do not wait for symptoms to appear.

Call your veterinarian or the nearest emergency animal hospital.
ASPCA Animal Poison Control Center: (888) 426-4435
Pet Poison Helpline: (855) 764-7661

A consultation fee may apply to the poison hotlines. Have the medication packaging ready, and note how much your pet may have taken and when. Do not try to make your pet vomit unless a veterinarian tells you to.

When to Call the Vet

If your dog experiences any of the following, contact your veterinarian or an emergency clinic immediately:

Signs of allergic reaction (facial swelling, hives, difficulty breathing)
Severe or bloody diarrhea
Vomiting persists after multiple doses
No improvement after 48-72 hours of treatment
Rash or skin irritation develops

Frequently Asked Questions

Frequently Asked · 07

Questions about this medication

Can I give my dog human amoxicillin?

While the active ingredient is the same, you should only give your dog amoxicillin prescribed by a veterinarian. Human formulations may contain different doses or inactive ingredients. Your vet needs to determine the correct dose and duration based on the type and severity of infection.

How much amoxicillin do I give my dog?

The typical dose is 5-10 mg per kilogram of body weight, given every 8-12 hours. For more serious infections, your vet may prescribe up to 25 mg/kg. The dose depends on the type and severity of infection, so always follow your vet's prescription.

How long does amoxicillin take to work in dogs?

Amoxicillin begins fighting bacteria within 1-2 hours, but visible improvement in symptoms usually takes 2-3 days. It's crucial to complete the entire prescribed course (typically 7-14 days) even if your dog seems better, to fully eliminate the infection and prevent resistance.

What are the side effects of amoxicillin in dogs?

The most common side effects are gastrointestinal, including diarrhea, nausea, and vomiting. These are usually mild. Serious allergic reactions (facial swelling, difficulty breathing) are rare but require immediate emergency care. Probiotics may help reduce digestive side effects.

Use This Guide Safely · 08

What weight alone cannot tell you

The calculator performs one narrow job: it multiplies your dog's weight by the lower, standard, and upper mg/kg values recorded for Amoxil. It cannot decide whether this drug, indication, formulation, or schedule is appropriate for an individual animal.

Context in this medication record

Commonly listed uses: bacterial infections, skin infections, urinary tract infections, respiratory infections, dental infections
Recorded forms: tablet, capsule, liquid suspension
Reference timing: every 8-12 hours; onset 1-2 hours; duration 8-12 hours

Individual checks a calculator cannot perform

Confirm the diagnosis and the reason this medication is being considered.
Match the exact product, concentration, route, and whether a tablet may be split.
Account for age, pregnancy, organ function, genetics, allergies, and prior reactions.
Review every prescription, over-the-counter product, and supplement your pet takes.

Recorded cautions

known penicillin allergy; known hypersensitivity; certain antibiotic-resistant infections.

Recorded interactions

methotrexate; anticoagulants; bacteriostatic antibiotics (may reduce effectiveness); allopurinol.

These lists reproduce the structured record used by this page and may not be exhaustive. Show your veterinarian the product label and your dog's complete medication list before acting on a number.

Related · 08

Related medications for dogs

Sources · 09

Sources & references

The structured medication record behind this page names the references below. The links open the publisher or official resource; they do not turn this page into a prescription for an individual animal.

Plumb's Veterinary Drug Handbook — listed in this medication's source record.
Merck Veterinary Manual — listed in this medication's source record.
DailyMed label search for Amoxicillin — check current product and formulation labels; some veterinary uses may be off-label.

Source names are shown at the record level; passage-level page and label citations are still being added. Read our methodology and limitations.

Transparency · 11

How this page was made

This page's structured medication record includes Plumb's Veterinary Drug Handbook among its source names. PetDosageChart applies the record's mg/kg values to the entered weight and presents the arithmetic result. A source record is not the same as an individualized prescription or an independent clinical review.

Sources cited: Plumb's Veterinary Drug Handbook
Merck Veterinary Manual
Calculator formula: Doses scale linearly from a standard basis of 10 mg per kg (4.54 mg per lb) of body weight, given every 8-12 hours. The calculator multiplies that basis by your dog's weight and shows an arithmetic comparison with recorded tablet sizes. That comparison does not determine whether a tablet is scored, splittable, or appropriate for your pet.
Editorial owner: Prepared and maintained by the PetDosageChart editorial team, a software-led publisher and not a veterinary practice.
DVM review status: Not independently DVM-reviewed. A named reviewer and review date appear here only after a confirmed review.

More on our methodology and editorial process — how we source, calculate, and review dogs dosage data.

Safety · 10

More resources

Pet Medication Safety Hub — What's safe, what's dangerous, and emergency signs
How we calculate dosages — Our sources, math, and review process
Printable emergency checklist — One-page reference for your fridge or first aid kit