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My dog has Giardia. Is Flagyl safe? What are the side effects?

Updated On September 23rd, 2025

Pet's info: Dog | Lhasa Apso | Male | unneutered | 1 year and 9 months old | 15 lbs

My dog has been diagnosed with giardiasis. The vet has prescribed Flagyl for 7 days than after 21 day to repeat the therapy for 7 days and after 21 day to repeat again for 7 days. I wanna hear different opinion and i am little bit worried about giving my dog Flagyl beacouse its antibiotic. Is there any chance Flagyl to do some harm to my dog. Like what are the side effects?

1 Answer

Most Helpful Answer

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Answered By Jessica Keay, DVM

Veterinarian

Published on May 21st, 2018

Metronidazole is a very commonly used drug to treat Giardia as well as other conditions. At a normal dose, Metronidazole rarely causes any side effects at all in pets. Nausea/decreased appetite would be the most common side effect (but once again, this is rare). At very high doses or long term dosing (taking nonstop for months) we can see neurological effects, but this do not occur at a dose that would be used to treat Giardia. You can read more about this drug at https://www.vin.com/veterinarypartner/default.aspx?pid=19239&id=4951414 .

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