Metronidazole Drug Information for Dogs and Cats

By: Dr. Alex Avery, BVSc | Reviewed by: Dr. Ryan Llera, B.Sc., DVM | Published by: Healthcare for Pets | May 17, 2019

Metronidazole Drug Information Sheet for Dogs and Cats

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Quick Info:


  • Drug name: Metronidazole
  • Common name: Flagyl, generics
  • Drug type: Antibiotic, antiprotozoal (type of parasite)
  • Used for: Bacterial and protozoa infections
  • Species: Dog + cat
  • Formulation: Injection, tablet, capsule


Name – Active Ingredient:


  • Metronidazole


Name – Common Trade Names:


  • Flagyl, generics






Major Indication:


  • The treatment of bacterial infection including those affecting the liver, colon, and intestines.
  • Protozoa infections, primarily Giardia.
  • It may help reduce the inflammation associated with inflammatory bowel disease.


Common Contraindications and Warnings:


  • Care is needed in animals with advanced liver disease.
  • Should not be used in pregnant or lactating animals.


Potential Side Effects:


  • Vomiting, inappetence and lethargy are most common and rarely diarrhea.
  • Other uncommon rare side effects include anorexia, bloody urine, and liver damage.
  • Overdose or long-term treatment can lead to nerve problems including wobbliness, head tilt, stiffness, tremors and seizures.


Administration Instructions/Handling:


  • Tablets are bitter, capsules can be easier to give.
  • Giving at the same time as food improves absorption but mixing with food may result in the food not being eaten.
  • If a dose is missed for more than a few hours, give when next due unless advised otherwise.




  • Protect from light and store at less than 30°C (86°F).


Speed of Action + Monitoring:


  • Antibiotics start working straight away but it can take several days for an effect to be seen depending on the type of infection and how long it has been present for.
  • If your pet is not recovering then culture and sensitivity testing may be needed (if it has not already been carried out) or the diagnosis re-evaluated.




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Metronidazole Drug Information for Dogs and Cats
Article Name
Metronidazole Drug Information for Dogs and Cats
This resource provides drug information for dogs and cats taking metronidazole.
Publisher Name
Healthcare for Pets
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