FDA Approves First Treatment for Giardia duodenalis in Any Animal Species

Oct. 25, 2023

October 11, 2023

Today the U.S. Food and Drug Administration approved Ayradia (metronidazole oral suspension) for the treatment of Giardia duodenalis infection in dogs. Ayradia is the first FDA-approved treatment for Giardia duodenalis for any animal species.

Giardia duodenalis is a common protozoal parasite that can infect the intestinal tract in dogs. Although Giardia can be present in healthy dogs, it can also lead to gastrointestinal infections that most commonly cause diarrhea, which can sometimes be severe. Giardia can be spread to other animals and is also a protozoal parasite with zoonotic potential, meaning it can spread to people.

Metronidazole has both anti-bacterial and anti-protozoal activities. Although veterinarians have historically prescribed a metronidazole product intended for humans when treating their animal patients for Giardia duodenalis, today’s approval means there is an approved product for dogs that has known safety and effectiveness for this species and is manufactured to quality standards.

The sponsor conducted a laboratory study and a field study to demonstrate the effectiveness of Ayradia to treat Giardia infections. In both studies, Ayradia effectively reduced the post-treatment counts of the Giardia parasite in treated dogs.

The most common adverse events in dogs treated with Ayradia were vomiting and diarrhea, which resolved without treatment.

Ayradia is only available by prescription from a licensed veterinarian because professional expertise is required to properly diagnose Giardia duodenalis infection in dogs and to monitor the safe use of the product, including treatment of any adverse reactions.

People with known sensitivity to metronidazole or other nitroimidazole products should avoid contact with Ayradia. Ayradia is a skin sensitizer, which can potentially cause allergic reactions. In case of skin contact, the affected area should be washed thoroughly. People who come in contact with a treated dog’s saliva during the first five minutes after administration should wash their hands. Although it is a best practice to always keep dog food away from children, pet owners should be particularly careful to keep dog food that has been mixed with Ayradia away from children.

Ayradia is administered orally at 25 mg/kg (11.3 mg/lb) of body weight, using the supplied syringe, twice daily for five consecutive days.

Ayradia is sponsored by Virbac AH, Inc., based in Fort Worth, Texas.