What is the recommended dose of Benadryl (diphenhydramine) for a 15-pound dog?

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Diphenhydramine Dosing for a 15-Pound Dog

The recommended dose of diphenhydramine (Benadryl) for a 15-pound dog is 15-30 mg (1-2 mg/kg) given orally every 8-12 hours as needed. 1

Dosage Calculation

  • For a 15-pound dog (approximately 6.8 kg), the appropriate dose range is 6.8-13.6 mg based on the 1-2 mg/kg dosing guideline 1
  • In practical terms, this translates to approximately 15-30 mg per dose, which is typically half to one 25 mg tablet or 5-10 ml of children's liquid formulation (12.5 mg/5 ml) 1
  • The medication can be administered every 8-12 hours as needed 1

Administration Guidelines

  • Oral administration is preferred for home use 1
  • Diphenhydramine can be given with or without food, though giving with food may help reduce potential stomach upset 1
  • For allergic reactions, the medication should take effect within 30 minutes 1

Indications for Use

  • Mild to moderate allergic reactions (hives, facial swelling, itching) 1
  • Motion sickness 2
  • Mild sedation (though research shows limited effectiveness for sedation in dogs) 2

Important Considerations

  • Diphenhydramine is considered a second-line therapy for allergic reactions; severe allergic reactions require immediate veterinary attention and epinephrine 1
  • The medication may cause drowsiness in some dogs, which is an expected side effect 2
  • Higher doses do not necessarily produce more sedation in dogs, as demonstrated in veterinary studies 2

When to Seek Veterinary Care

  • For severe allergic reactions (difficulty breathing, collapse, severe swelling) seek immediate veterinary care 1
  • If symptoms don't improve within 24 hours of administering diphenhydramine 1
  • If the dog has pre-existing medical conditions or is taking other medications 3

Potential Side Effects

  • Drowsiness/sedation (most common) 2
  • Dry mouth 3
  • Urinary retention 3
  • Rarely, paradoxical excitation 3

Remember that while diphenhydramine is generally safe for dogs when used appropriately, any medication should ideally be used under veterinary guidance, especially for ongoing conditions.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Evaluation of diphenhydramine as a sedative for dogs.

Journal of the American Veterinary Medical Association, 2005

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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