Generic drug for treating internal parasites in sheep receives FDA approval

Officials with the FDA have approved a generic moxidectin product for the treatment and control of internal parasites in sheep. The application for the product, Moxidectin Oral Drench for Sheep, is sponsored by from First Priority Inc., an Illinois-based manufacturer of animal care products and generic drugs.¹

The FDA has determined that Moxidectin Oral Drench for Sheep is bioequivalent to the brand-name drug Cydectin Oral Drench for Sheep (Elanco Animal Health), which was approved by the agency in 2005. Both products contain the same active ingredient: moxidectin.^1,2

Moxidectin Oral Drench for Sheep is available over the counter in 1-liter and 4-liter bottles. According to the FDA, “the recommended the rate of administration into a sheep’s mouth is 1 mL per 11 lbs. (1 mL per 5 kg) of body weight, which provides a dose level of 0.2 mg moxidectin per 2.2 lbs. (0.2 mg/kg) body weight.”¹

The FDA has determined Moxidectin Oral Drench in Sheep to be effective for treatment and control of adult and larval stages of certain internal parasites of sheep, when used at the recommended dose level.¹ These parasites are gastrointestinal nematodes (or roundworms) including Haemonchus contortus, Teladorsagia circumcincta, Teladorsagia trifurcata, Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus vitrinus, Cooperia curticei, Cooperia oncophora, Oesophagostomum columbianum, Oesophagostomum venulosum, Nematodirus battus, Nematodirus filicollis and Nematodirus spathiger.²

Moxidectin Oral Drench in Sheep should not be used in female sheep providing milk for human consumption because a withholding time in milk has not been established, according to the FDA. Additionally, “sheep must not be slaughtered for human consumption within 7 days of treatment,” the agency said in a news release.¹

References

1. FDA approves first generic moxidectin oral drench for treatment of internal parasites in sheep. News release. FDA. April 29, 2026. Accessed April 30, 2026. https://www.fda.gov/animal-veterinary/cvm-updates/fda-approves-first-generic-moxidectin-oral-drench-treatment-internal-parasites-sheep
2. Freedom of Information (FOI) Summary: ANADA 200-852. FDA April 29, 2026. Accessed April 30, 2026. https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/18369