Metronidazole vs Tylosin: what's the difference?
How Metronidazole and Tylosin compare: what each is for, how it works, side effects and cost, side by side.
Last updated: October 2026 · 2 sources · see sources
Side by side
| Metronidazole | Tylosin | |
|---|---|---|
| Generic name | Metronidazole | Tylosin |
| Brand names | Flagyl | Tylan |
| For | Dogs and cats | Dogs and cats |
| Prescription | Prescription | Prescription |
| Used for | Treats certain bacterial and protozoal infections, such as Giardia, and is often used for diarrhea. [1] | An antibiotic used mainly for diarrhea and gut inflammation. [2] |
| How it works | It kills anaerobic bacteria and some single-celled parasites by damaging their DNA. [1] | A macrolide antibiotic related to erythromycin. [2] |
| Common side effects | Nausea, vomiting, diarrhea, low appetite, tiredness and drooling. It tastes very bitter. [1] | Mild stomach upset and, with the injection, soreness at the site. [2] |
| Use with care | Not for pregnant or nursing pets or very weak pets. Stop and call your vet if your pet seems wobbly, weak or unwell. [1] | The powder tastes bitter, so it is often hidden in food or put in capsules. [2] |
| Full guide | Metronidazole (Flagyl) guide | Tylosin guide |
Key differences
On the basics they are alike: same kind of animal, same way to get them. The differences are in how they work and what else they cover, shown in the table above.
Which one is right for my pet?
That is a call for your vet. They weigh your pet's age, weight, other health problems, other medicines and what you can realistically give at home.
Switching from Metronidazole to Tylosin is common, but do it only with your vet's plan.
Common questions
What is the difference between Metronidazole and Tylosin?
Both are antibiotics vets use for diarrhea. Metronidazole also works on some parasites such as Giardia.
Is Metronidazole better than Tylosin?
Neither is better for every pet. Your vet chooses based on your pet's species, age, health history, other medicines and what you can manage at home.
Can my pet take Metronidazole and Tylosin together?
Only if your vet says so. Some medicines in the same family should not be combined, and others are often used together. Always check before adding or switching.
Do Metronidazole and Tylosin need a prescription?
Metronidazole: Yes. It needs a prescription from a veterinarian. Tylosin: Yes. It needs a prescription from a veterinarian.
Related
This page is general information for planning, not veterinary advice. Talk to your vet about your own pet.