Merck Animal Health

Merck Animal Health is the animal health division of Merck & Co., Inc., which is headquartered in Rahway, New Jersey, and listed on the New York Stock Exchange (NYSE: MRK). The division uses the Merck Animal Health name in the United States and Canada and operates as MSD Animal Health elsewhere. Its corporate headquarters is at 126 East Lincoln Avenue, Rahway, NJ 07065. The business sells vaccines, medicines, parasiticides and technology products for companion animals, horses, swine, poultry, ruminants and aquaculture, and says it is present in more than 150 countries. In fiscal year 2025, Merck reported Animal Health sales of USD 6.354 billion, up 8% (9% excluding foreign exchange). Livestock products accounted for USD 3.896 billion, up 13%, and companion animal products for USD 2.458 billion, up 2%.

Merck Animal Health's digital livestock business centres on identification and on-animal monitoring. Merck built this business by acquiring Antelliq Corporation, a deal completed on 1 April 2019. Antelliq's brands included Allflex Livestock Intelligence, Sure Petcare and Biomark. At the time, Antelliq made devices for animal identification, monitoring and traceability, along with data services for livestock, fish and pets, and had 22 production sites serving more than 100 countries. Merck described the acquisition as making it a leader in emerging digital technology for livestock and companion animals.

The main livestock monitoring product line is SenseHub, which grew out of the SCR Dairy technology that entered the North American market in 2008. SenseHub Dairy uses neck collars and ear tags to monitor rumination, heat (oestrus), general health and other behaviours that feed more complex analyses. Merck says this line introduced the dairy industry's first rumination monitoring technology and the first LED light-enabled monitoring ear tag, which helps staff find individual animals. In August 2025, Merck Animal Health reported that SenseHub Dairy was monitoring more than 2 million dairy cows in the United States, four years after passing 1 million in 2021.

The platform has since expanded beyond lactating cows. In October 2024, the company introduced SenseHub Dairy Youngstock, which has since been extended to monitor bucket-fed calves. A SenseHub Beef solution covers beef cows. The Allflex brand continues to cover animal identification ear tags, with separate contact channels for identification and for livestock monitoring orders.

Merck Animal Health uses the tagline "The Science of Healthier Animals." The division supports veterinarians, farmers, producers and pet owners. For US customers, it runs technical services and adverse-event reporting lines for companion animals, horses and livestock. Its monitoring products put sensors and software into dairy and beef operations, while its core business remains pharmaceuticals and biologicals.