Merck expands access to Exzolt for backyard hens facing mite infestations

Merck Animal Health has broadened the availability of its oral mite treatment, Exzolt, to backyard laying hens and replacement chickens, offering an easy-to-administer solution to northern fowl mite infestations, now approved by the FDA with proven high efficacy.

Merck Animal Health has expanded access to Exzolt, its fluralaner oral solution, for backyard laying hens and replacement chickens facing northern fowl mite infestations. According to the company, the treatment is mixed into drinking water and given in two doses seven days apart, avoiding injections and the need to catch each bird individually.

The product was first cleared by the US Food and Drug Administration in July 2025, after review linked to research at Pennsylvania State University’s College of Agricultural Sciences. The FDA said at the time that Exzolt was the first oral product approved in the US for northern fowl mites in poultry.

Northern fowl mites can damage bird comfort, welfare and egg output, and although they do not usually live on people or pets, they can still bite and irritate household members. Merck says Exzolt begins working within hours, offers 99.9 per cent efficacy in studies, and carries a zero-day egg withdrawal period and an 11-day meat withdrawal period.

Dr Charles Broussard, Merck Animal Health senior account manager for poultry sales, said backyard owners need “effective parasite control options that are easy to use and protect the health of their birds without disrupting daily care”.