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PetDosageChart

Serotonin (5-HT3) receptor antagonist antiemetic · For Dogs · 100 lb

How much Zofran for a 100 lb dog?

A 100 lb dog (45.4 kg) should receive approximately 34.0 mg of Zofran per dose, given Every 8-12 hours.

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. Sourced from Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage · 100 lb dog

Zofran dose for a 100 lb dog

Low Dose

22.7

mg

Standard

34.0

mg

Max Safe

45.4

mg

Frequency

Every 8-12 hours

Weight in kg

45.4 kg

Always confirm with your veterinarian before administering medication. These calculations are estimates based on published veterinary pharmacology references.

Other Weights

Zofran for a different size dog

FAQ · 100 lb dog

Questions about Zofran for a 100 lb dog

How much Zofran for a 100 lb dog?
A 100 lb dog should receive approximately 34.0 mg of Zofran (Ondansetron) per dose, given Every 8-12 hours. That works out to about 8.5 × 4 mg. Always confirm with your veterinarian before administering medication.
What is the safe dose range of Zofran for a 100 lb dog?
The published dose range for a 100 lb dog is roughly 22.7 mg (low) to 45.4 mg (max safe), with 34.0 mg as the typical standard dose. Frequency: Every 8-12 hours.
How often can I give Zofran to a 100 lb dog?
Zofran is typically given Every 8-12 hours. Do not exceed the recommended frequency without veterinary guidance.

Need a different weight?

Use the calculator on the main Zofran page for any exact weight, or read the full dosage chart and safety information.

Full Zofran dosage guide →

Sources · 09

Sources & references

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Ondansetron.

Read more about our methodology and how we calculate dosages.