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Ornidazole

Prescription
Nitroimidazole Antiprotozoal / Antibacterial
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
2 available
Formulations
3

Mechanism of action

Nitroimidazole that disrupts DNA of anaerobic organisms and protozoa after intracellular reduction. Active against Giardia, Trichomonas, Entamoeba, and anaerobic bacteria.

At a glance

Class
Nitroimidazole Antiprotozoal / Antibacterial
Schedule
Prescription
Storage
Store at room temperature, protect from light

Dosing

🐕

Dog

Used for giardiasis, anaerobic infections, and amoebic dysentery
Dose
30 mg/kg
Route
PO
Frequency
q24h
🐈

Cat

Alternative to metronidazole in cats; monitor for neurological side effects
Dose
30 mg/kg
Route
PO
Frequency
q24h
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 3

Strength
Strength
Strength

Storage

Store at room temperature, protect from light

Safety

Monitoring parameters

Neurological statusLiver enzymes with prolonged use
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

No documented interactions.

Brands

Other markets

Ornida
Dazolic

FAQs

Frequently asked questions

What is Ornidazole?
Ornidazole is a nitroimidazole antiprotozoal / antibacterial used in pets. Nitroimidazole that disrupts DNA of anaerobic organisms and protozoa after intracellular reduction. Active against Giardia, Trichomonas, Entamoeba, and anaerobic bacteria.
What is Ornidazole used for in pets?
Ornidazole is used in veterinary medicine for: Used for giardiasis, anaerobic infections, and amoebic dysentery; Alternative to metronidazole in cats; monitor for neurological side effects.
What is the Ornidazole dose for dogs?
For dogs, Ornidazole is typically dosed as follows — Used for giardiasis, anaerobic infections, and amoebic dysentery: 30 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Ornidazole dose for cats?
For cats, Ornidazole is typically dosed as follows — Alternative to metronidazole in cats; monitor for neurological side effects: 30 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Ornidazole need a prescription?
Yes. Ornidazole is a prescription medication and should only be administered under veterinary supervision.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database

Related medicines

Other medicines in the same class (Nitroimidazole Antiprotozoal / Antibacterial).

Tinidazole
Rx
Second-generation nitroimidazole with longer half-life than metronidazole. Intracellular reduction generates reactive metabolites that damage protozoal and anaerobic bacterial DNA. Active against Giardia, Trichomonas, Entamoeba, and anaerobes.
dogcat
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