RAHWAY, N.J. — December 3, 2025 — Mexico’s Secretariat of Agriculture and Rural Development (SADER) has granted approval for MSD Animal Health’s EXZOLT® 5% Pour-On (fluralaner 50 mg/mL), a next-generation parasiticide designed for the prevention and treatment of New World Screwworm (Cochliomyia hominivorax) larvae, a damaging infestation that poses rising threats to cattle health and national livestock productivity. With this approval, veterinarians and producers now have a powerful systemic tool to protect herds, reduce morbidity, and strengthen Mexico’s beef supply chain at a time when parasite resistance and cross-border disease pressures are mounting.
Science Significance
This approval underscores the scientific importance of isoxazoline-class parasiticides, marking EXZOLT 5% Pour-On as an innovative systemic solution that delivers fluralaner transdermally to disrupt parasite development and eliminate larvae effectively. The product demonstrated high efficacy and safety in global studies, including a CENAPA-led clinical evaluation in Mexico, validating its ability to prevent severe myiasis and reduce parasite-driven morbidity. As resistance continues to erode the effectiveness of older parasiticides, this new mechanism enriches the scientific toolkit for integrated parasite management, enhancing veterinary ability to mitigate emerging parasitic threats.
Regulatory Significance
SADER’s authorization signals a major regulatory milestone in the region’s continued defense against screwworm, a parasite associated with high mortality, rapid tissue damage, and severe economic loss. The approval confirms that EXZOLT met Mexico’s stringent safety and effectiveness standards, aligning veterinary product oversight with international scientific benchmarks. The decision further positions MSD Animal Health to seek additional international approvals, supporting harmonized regulatory frameworks aimed at reducing disease spread across borders, especially in regions vulnerable to screwworm reintroduction.
Business Significance
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For Mexico’s growing livestock sector, EXZOLT offers an important advancement in maintaining healthy, productive herds, reducing preventable losses, and supporting stable output for domestic and export markets. For MSD Animal Health, the approval strengthens its leadership in the global antiparasitic market and enhances its product portfolio with a high-value innovation at a time of increasing demand for effective, resistance-mitigating parasiticides. The product’s introduction may catalyze additional investments in R&D, supply chain readiness, and regional market expansion, reinforcing MSD Animal Health’s long-term commercial strategy across Latin America.
Patients’ Significance
Livestock producers across Mexico now gain access to a clinically validated preventative therapy that addresses one of the region’s most damaging parasitic threats. By reducing the incidence of myiasis, EXZOLT supports better animal welfare, decreases the need for emergency treatments, reduces pain and tissue destruction, and improves the overall condition and performance of herds. Healthier animals translate to higher productivity, fewer losses, and safer food products, benefiting both producers and consumers. Early preventative use also reduces the risk of widespread outbreaks that could jeopardize the national beef supply.
Policy Significance
SADER’s approval aligns with national agricultural protection goals aimed at strengthening biosecurity, disease control, and livestock resilience. The decision supports policies intended to safeguard Mexico’s economic stability in livestock production and mitigate risks from parasitic disease incursions, especially in areas near the U.S. border where screwworm is monitored closely. This approval also reinforces global calls for science-driven parasiticide deployment, emphasizing preventive strategies over reactive crisis management and contributing to national agricultural sustainability priorities.
With the approval of EXZOLT 5% Pour-On, Mexico takes a proactive step in combating the growing threat of New World Screwworm, equipping veterinarians and cattle producers with a modern, evidence-based tool backed by international research and local clinical validation. As MSD Animal Health continues working with regulatory bodies worldwide, this milestone marks significant progress toward strengthening animal health infrastructure, enhancing livestock productivity, and ensuring long-term resilience for one of the country’s most vital agricultural sectors.
Source: MSD Animal Health press release
