Amoxicillin Dosage and Guidelines for Dogs

Amoxicillin is a widely used, broad-spectrum antibiotic prescribed by veterinarians to treat a variety of bacterial infections in dogs. Its effectiveness against many gram-positive and gram-negative bacteria makes it a go-to option for respiratory, urinary, gastrointestinal, skin, ear, and dental infections.

Standard Dosage Recommendations

The standard recommended dosage for dogs is 5 mg per pound (lb) of body weight, administered orally every 12 hours (twice daily). For example, a 40-lb dog would typically receive 200 mg per dose, given two times daily. The duration usually ranges from 5–7 days or at least 48 hours after symptoms resolve. In some cases—especially persistent or severe infections—courses may last up to 10–14 days or longer as directed by the veterinarian.

Dose: 5 mg/lb every 12 hours (oral)
Maximum guideline dose: Up to 10 mg/lb every 12 hours (per veterinary discretion)
Duration: Typically 5–7 days; longer if infection persists
Formulations: Tablets, capsules, liquid oral suspension

Dosing and duration are always tailored by the veterinarian based on infection type, severity, your dog's health status, and response to therapy. Never adjust the dose or stop treatment early without veterinary guidance.

Administration Tips

You can give amoxicillin with or without food; however, administering it with meals may help reduce gastrointestinal side effects. Tablets or capsules can be hidden in small amounts of food or inside pill pockets—just make sure your dog consumes the entire dose. Liquid suspensions are also available and may be easier for some pets.

If you miss a dose and it's almost time for the next one, don't double up—just resume the regular schedule.
The full course must be completed even if your dog appears better before finishing all medication. Stopping early can lead to recurrence or resistance.
Give doses at consistent intervals (every 12 hours) to maintain effective levels in your dog's system.

Precautions and Contraindications

Amoxicillin should not be given to pets with known allergies to penicillins, cephalosporins, or beta-lactam antibiotics. It's also unsafe for rabbits, guinea pigs, chinchillas, and hamsters due to risk of life-threatening diarrhea. Use caution in very young puppies or pregnant/lactating dogs; your vet will weigh risks versus benefits in these cases.

Possible Side Effects

The most common side effects are mild gastrointestinal issues such as vomiting, diarrhea, loss of appetite, abdominal pain, or lethargy. Serious allergic reactions are rare but require immediate veterinary attention. Watch for:

Rash or hives
Facial swelling
Trouble breathing
Persistent vomiting/diarrhea
Lethargy or fever
(Rarely) seizures or tremors in overdose situations

If you notice any signs of allergy or overdose (such as severe nausea/vomiting, neurological symptoms), stop giving the medication and contact your veterinarian right away.

Drug Interactions and Safety Measures

Certain drugs may interact with amoxicillin—including other antibiotics (especially bacteriostatic types), methotrexate, probenecid, allopurinol, and warfarin. Always inform your vet about all medications and supplements your dog is taking before starting antibiotics.

Avoiding Human Formulations Without Veterinary Guidance

Never give human-formulated amoxicillin to your dog unless specifically prescribed by a veterinarian. Human products may contain additives (like xylitol) that are toxic to pets or have inappropriate concentrations. Only use veterinary-prescribed medications with clear dosing instructions.

Cultures and Resistance Prevention

Your vet may recommend a culture and sensitivity test if an infection isn't responding well to treatment. This helps confirm that amoxicillin is appropriate for the specific bacteria involved and reduces the risk of resistance development.

Storage Instructions

Store tablets/capsules at room temperature away from moisture/light.
If using liquid suspension: Refrigerate after mixing; use within time specified on label (often 14 days).
Keep all medications out of reach of children and pets.

The Importance of Veterinary Oversight

Your veterinarian will determine whether amoxicillin is suitable based on your dog's health history and infection type. Brand names include Amoxi-Tabs, Amoxi-Drops, Bimox, and Novamoxin—these require a prescription from a licensed vet. Never use leftover antibiotics from previous illnesses without approval; improper use increases risks of resistance and complications.

If you have concerns about cost or access to medications through pharmacies (including discount programs), discuss options with your veterinary clinic—they can guide you safely through legal channels.

The bottom line: Amoxicillin is generally safe when prescribed correctly for dogs but requires careful adherence to dosing guidelines provided by your veterinarian. Complete the full course as directed—even if symptoms improve—and report any side effects promptly for best results in treating bacterial infections while safeguarding your pet's long-term health.

Learn: Respiratory infections