FDA Approves First Generic Fenbendazole Oral Suspension Dewormer for Beef and Dairy Cattle, Goats
January 22, 2026
The U.S. Food and Drug Administration has approved Defendazole (fenbendazole) oral suspension to treat and control various species of lungworms, stomach worms and intestinal worms in beef and dairy cattle, and to treat and control two species of stomach worms in goats.
Defendazole contains the same active ingredient (fenbendazole) as the approved brand name drug product, Safe-Guard (NADA 128-620), which was first approved for both cattle and goats in 1994. The FDA determined that Defendazole oral suspension is bioequivalent to the brand name product.
When Defendazole is used in cattle according to label directions, there is an 8-day withdrawal time for cattle and a 48-hour milk discard time. For goats, there is a 6-day withdrawal period.
Defendazole is available over the counter in 1 L and 5 L bottles. Dosage is 2.3 mg/lb (5mg/kg) body weight for beef and dairy cattle, and 2.3 mg/lb (5 mg/kg) body weight for goats.
Defendazole is sponsored by Norbrook Laboratories Ltd. based in the United Kingdom.
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