MSD Animal Health, a division of Merck & Co., Inc. (NYSE:MRK), announced on June 12, 2025, that the European Medicines Agency’s Committee for Medicinal Products for Veterinary Use (CVMP) issued a positive opinion for its new NOBIVAC® L6 and LoVo L6 vaccines.

If adopted by the European Commission later this year, these would become the first and only canine leptospirosis vaccines approved in the EU to offer broad protection—reducing or preventing mortality, clinical signs, infection, urinary excretion, and kidney damage caused by six Leptospira serovars.

The approval comes at a time when leptospirosis is resurging globally, driven by a combination of climate change, intensified rainfall and flooding, urban expansion, and shifting rodent populations. These environmental dynamics are increasing exposure risks not only for outdoor dogs but also for indoor pets in densely populated areas. According to MSD Animal Health’s global technical director, Dr. Melissa Bourgeois, the expanded claims of the new vaccines reflect this changing risk landscape.

Leptospirosis is a zoonotic disease that can transmit from dogs to humans, making it both a veterinary and public health concern. Outbreaks can carry high economic costs through treatment, diagnostics, and risk mitigation—particularly in high-density or flood-prone regions. Preventive vaccination is widely considered the most cost-effective approach.

In line with global recommendations, including updated WSAVA guidelines, MSD’s new vaccines are designed for primary use from six weeks of age, with annual boosters. If approved, the products would expand the NOBIVAC® portfolio and strengthen MSD’s global position in the fast-growing preventive care segment for companion animals.

More information is available at www.msd-animal-health.com/