What Is Metronidazole?
Discover how veterinarians use metronidazole to treat diarrhea and gut infections in dogs and cats. Learn about its uses, side effects, and top brands available in the U.S.
Metronidazole is a prescription antibiotic and antiprotozoal medication commonly prescribed by veterinarians in the U.S. to treat diarrhea, intestinal infections, and inflammatory bowel disease (IBD) in pets—especially dogs and cats.
It is often used to target anaerobic bacteria and parasites such as Giardia, which are common causes of gastrointestinal upset in pets.
When Is Metronidazole Prescribed for Pets?
Veterinarians often prescribe metronidazole to treat:
Diarrhea caused by bacterial or protozoal infections
Giardia infections
Colitis or inflammatory bowel disease (IBD)
Dental infections and abscesses
Post-surgical or deep wound infections
It’s typically used off-label for pets, which is legal and common in veterinary practice when guided by a licensed veterinarian.
How It Works
Metronidazole works by:
Disrupting the DNA of anaerobic bacteria and protozoa
Reducing inflammationin the gastrointestinal tract
Stopping the spread of infection and restoring normal gut function
It is available in tablet, capsule, and liquid forms for both small and large animals.
Dosage and Administration
Dosage depends on your pet’s weight, species, and diagnosis
Usually given once or twice daily for 5 to 10 days
Should be administered with food to reduce the risk of nausea
Must be completed as prescribed, even if symptoms improve early
Always follow your veterinarian’s instructions precisely.
Potential Side Effects
Most pets tolerate metronidazole well, but possible side effects include:
Vomiting or loss of appetite
Lethargy or weakness
Drooling or nausea
Neurological signs (rare at high doses): stumbling, head tilt, seizures
Seek veterinary attention if any unusual symptoms occur.
Safety Tips
Never use metronidazole without a vet’s prescription
Do not double doses if a dose is missed
Store in a cool, dry place, away from children or other animals
Avoid long-term use without close supervision due to potential neurological risks