Metronidazole, the popular brand name Flagyl is an anti-diarrheal medication for humans. Metronidazole For cats is used to treat mild to severe diarrhea.
The medicine also has many other veterinary uses, such as treating certain protozoal infections and anaerobic bacterial pathogens in cats and dogs.
Beside these uses Metronidazole can also be used to treat certain inflamations of gastro intestinal tract and can also be used to treat dental infections.
Metronidazole is not FDA-approved for pets use; however it can be used off-label to treat diarrhea, IBD, and other issues in cats.
It’s important to follow your veterinarian’s dosage instructions closely, as higher doses can be toxic to cats.
In this article, we’ll discuss the recommended metronidazole dosage for cats, other uses, benefits as well as some potential side effects. A dosage calculator is available for every form of the medicine.

What is safe Metronidazole Dosage For cats?
The safe dosage of metronidazole to treat cat diarrhea is 7-10 mg/kg or 3-5 mg/lb twice daily. For the treatment of Giardia infection in felines, the recommended dose of metronidazole is 10-25 mg/kg twice daily for 5 days. The dosage of Flagyl metronidazole liquid suspension 200mg/5ml for cats is 0.18 ml/kg.
Remember that the dose of any feline medication depends on several factors, including the weight of the body, health issues, severity of the illness, and overall health condition of the cat.
Your veterinarian can increase or decrease the dosage after observing your feline health issue physically.
Metronidazole Dosage Calculator For cats
Metronidazole Dosage chart by weight For cats
Cat Weight kg | Cat Weight lbs | Metronidazole Dosage |
---|---|---|
2 kg | 4 lbs | 14-20 mg |
3 kg | 7 lbs | 21-30 mg |
4 kg | 9 lbs | 28-40 mg |
5 kg | 11 lbs | 35-50 mg |
6 kg | 13 lbs | 42-60 mg |
7 kg | 15 lbs | 49- 70 mg |
8 kg | 18 lbs | 56-80 mg |
9 kg | 20 lbs | 63-90 mg |
10 kg | 22 lbs | 70-100 mg |
To follow the Metronidazole Dosage chart by weight For cats, For safety, we suggest always sticking with the low dose until your vet advises to increase the dose.
Flagyl Liquid Suspension Dosage Chart For Cats
The ideal form of using Metronidazole for felines is to use the liquid form. Liquid Flagyl is easier to administer to cats as compared to tablet forms.
Cat Weight in kg | Feline Weight in lbs | Flagyl Liquid Suspension Dosage |
---|---|---|
2 kg | 4 lbs | 0.36 ml |
3 kg | 7 lbs | 0.54 ml |
4 kg | 9 lbs | 0.72 ml |
5 kg | 11 lbs | 0.9 ml |
6 kg | 13 lbs | 1 ml |
7 kg | 15 lbs | 1.26 ml |
8 kg | 18 lbs | 1.44 ml |
9 kg | 20 lbs | 1.62 ml |
10 kg | 22 lbs | 1.8 ml |
The above Flagyl Liquid Suspension Dosage Chart for felines is based on the liquid 200mg/5ml of Flagyl.
Flagyl Suspension Dosage Calculator For Cats
Can I give my cat Flagyl 400mg?

Yes, you can give your cat Flagyl 400mg. However, make sure to divide the tablet into a safe dosage for your kitty
Don’t give a whole 400mg tablet to your cat. Overdosing can be fatal. Please note that Flagyl 400mg should only be used under the advice and supervision of a veterinarian.
Flagyl Tablets Dosage Chart for cats
kg Weight | lbs Weight | Flagyl 250 mg for cats Dosage | Flagyl 400 mg Dosage for cats | Flagyl 500 mg cats Dosage |
---|---|---|---|---|
5 kg | 11 lbs | 1/5 Tablet | Not Recommended | Not Recommended |
6 kg | 13 lbs | 1/4 Tablet | Not Recommended | Not Recommended |
7 kg | 15 lbs | 1/4 Tablet | 1/6 Tablet | Not Recommended |
8 kg | 18 lbs | 1/3 Tablet | 1/5 Tablet | Not Recommended |
9 kg | 20 lbs | 1/3 Tablet | 1/5 Tablet | 1/6 Tablet |
10 kg | 22 lbs | 1/3 Tablet | 1/4 Tablet | 1/5 Tablet |
Which cats should not take Metronidazole?
Metronidazole should not be given to pregnant cats or kittens under six weeks old. Felines with liver or kidney disease may also be at risk for adverse reactions when taking Metronidazole.

Cats allergic to the medicine and suffering from debilitated or liver dysfunction should not take Metronidazole until your veterinarian advises.
Metronidazole should not be used in pregnant or nursing cats, as it can cause congenital disabilities or fetal death.
Metronidazole can also enter a cat’s milk and may harm young kittens, so nursing felines should not take the medications.
Side effects of Metronidazole in Cats
The most reported side effects of Metronidazole in felines are:
- Vomiting
- Mouth foaming
- Drooling and gagging
- Irregular Eye movements
- Depression and disorientation
- Restlessness
Metronidazole Toxicity in Cats
Among pets, felines are more susceptible to the toxic effects of metronidazole, and even a small overdose can lead to serious health problems.
Symptoms of metronidazole toxicity in cats include vomiting, Stiffness, appetite loss, weight loss, Tremors, lethargy, and seizures, Blood in the urine and Liver damage.
If your cat has any of these symptoms after taking metronidazole, it is important to seek veterinary care immediately.
How long does metronidazole take to start its work?
Metronidazole starts to work against infections within a few hours about 2-4 hours. However, you may not notice any improvement in your symptoms for the first few days of treatment.
For some types of infections, it may take a week or two of treatment before your symptoms start to improve.
You May Also Like To Read:
- Methimazole for Cats: Felimazole Dosage Chart by Weight
- Safe Cetirizine Zyrtec Dosage For Cats Chart and How to Use?
Which medecine can interact with metronidazole?

Metronidazole Flagyl can interact with certain medicines. Ensure to inform your vet before using this anti-diarrheal medicine for your kitty.
medicine interact with metronidazole are:
- Warfarin
- Cimetidine
- Phenytoin
- Phenobarbital
- Cyclosporine
- Fluorouracil
Metronidazole for cats length of Treatment
A veterinarian can better decide the duration of the treatment more accurately. However, in general, To treat cat diarrhea, the length of metronidazole treatment is 4-8 days.
For the treatment of Giardia infection, five days of treatment is required.
Popular Brand Names:
- Flagyl®
- Metric 21®
- Protostat®
- Metro®
How to administer Metronidazole for cats?

1. Metronidazole is a prescription medication that is used to treat various infections in cats.
2. The recommended dosage can be given by mouth every 8-12 hours for 7-10 days.
3. Metronidazole can be given with or without food, but if your cat vomits after taking it on an empty stomach, try giving it with food next time.
4. Some common side effects of Metronidazole include diarrhea, appetite loss, and vomiting. Contact your vet if you observe an adverse reaction.
5. Metronidazole should not be used in pregnant or nursing cats, as it can be passed to the kittens through milk.
6. If you are giving Metronidazole to a kitten, be sure to follow the dosage instructions closely, as kittens are more sensitive to the medication than adult cats.
7. Metronidazole can interact with other medications, so be sure to tell your veterinarian about any other drugs your cat is taking before starting Metronidazole.
8. The dosage and length of treatment will vary depending on the condition being treated.
9. Flagyl can be given orally or intravenously.
10. Metronidazole should not be used in animals with known hypersensitivity or allergy to the drug.
Can I use metronidazole for cats vomiting?
Metronidazole is not an effective medication for treating cat vomiting. You should not use metronidazole for cats vomiting. There are other medications that are more effective and safe for vomiting cats.

