FDA approves dewormer for home use in chickens

Photo: cherryandbees/Adobe Stock

Photo courtesy of Merck Animal Health

Officials with the FDA have approved fenbendazole oral suspension (Safe-Guard Aquasol; Merck Animal Health) for treating parasitic roundworms in chicken flocks. According to Merck, the drug product was designed for use with backyard flocks.¹

Fenbendazole oral suspension is indicated for the treatment and control of adult Ascaridia galli in broiler and replacement chickens, and for the treatment and control of adult A galli and Heterakis gallinarum in breeding chickens and laying hens. The drug is the only chicken dewormer designed for home use that has been approved by the agency, according to Merck.^1,2

A galli affects the small intestines of chickens, and other bird species. This roundworm is associated with anemia and emaciation as well as decreasing the production of eggs and meat. Although A galli in the larval stages have a major role in pathology, both adult and young parasites affect the gut health of chickens.³

H gallinarum thrives in chickens’ ceca. It is prevalent in poultry and large numbers of birds raised in small areas are thought to be a higher risk of this parasitic disease. Although H gallinarum typically causes mild pathology and does not significantly affect bird performance, this parasite is a vector for Histomonas meleagridis, which causes histomonosis in birds.⁴

“Chicken flocks of any size can be affected by intestinal parasites, leading to animal welfare concerns and decreased production efficiency. Safe-Guard Aquasol effectively treats common intestinal parasites in the average-sized backyard flock with the added benefit of no meat or egg withdrawal,” Blayne Mozisek, DVM, livestock insights and outcomes for Merck Animal Health, said in a news release.¹

Fenbendazole oral suspension is administered daily by adding a dose of 1 mg/kg BW (0.454 mg/lb) to drinking water for 5 consecutive days. This medicated water should be prepared each day before administration.²

Six pivotal dose confirmation studies and 5 field effectiveness studies were conducted to determine the efficacy of fenbendazole oral suspension against A galli in broiler and replacement chickens; and A galli and H gallinarum in breeding chickens and laying hens. These studies demonstrated evidence that supports effectiveness at the dose, body weight, and duration indicated by the FDA’s approval.²

A pair of margin of safety studies also demonstrated no clinically significant effects for the evaluated parameters were shown in chickens that were administered fenbendazole oral suspension. However, protective gloves should be used by humans and care should be taken when handling the product to avoid skin and eye exposure and accidental ingestion. Exposure in humans may result in skin and eye irritation and may cause gastrointestinal disturbances and hypersensitivity reactions.²

The newly approved drug product will be available in a 3 mL presentation at fleet and dealer retail outlets beginning in January 2025, according to Merck. Clients should be advised to consult a veterinarian for assistance in diagnosing, treating and controlling parasitism in their chickens.^1,2

References

1. Merck Animal Health announces FDA approval of Safe-Guard Aquasol (fenbendazole oral suspension) for use in backyard chickens. News release. Merck Animal Health. November 13, 2024. Accessed November 21, 2024. https://www.merck-animal-health-usa.com/newsroom/merck-animal-health-announces-fda-approval-of-safe-guard-aquasol-fenbendazole-oral-suspension-for-use-in-backyard-chicken-flocks
2. Safe-Guard Aquasol. Product label. Merck Animal Health. March 2024. Accessed November 21, 2024. https://assets.morganmyers.com/NewsReleasePhotos/Safe-Guard%20AquaSol%20Product%20Insert.pdf
3. Shohana NN, Rony SA, Ali MH, et al. Ascaridia galli infection in chicken: pathobiology and immunological orchestra. Immun Inflamm Dis. 2023;11(9):e1001. doi:10.1002/iid3.1001
4. Cupo KL, Beckstead RB. Heterakis gallinarum, the cecal nematode of gallinaceous birds: a critical review. Avian Dis. 2019;63(3):381-388. doi:10.1637/0005-2086-63.3.381