AHN Highlights
- Approval: U.S. FDA label expansion, October 2025
- New claims: Prevention of Lyme disease via control of black-legged ticks; treatment and control of longhorned tick infestations
- Tick coverage: Black-legged, lone star, brown dog, American dog, and longhorned ticks
- Efficacy: 100% efficacy against longhorned ticks within 48 hours (peer-reviewed study)
- Lyme disease trends: 422,000+ canine cases reported in 2025 (CAPC data)
The U.S. Food and Drug Administration (FDA) has approved label expansions for Elanco Animal Health’s Credelio™ (lotilaner) and Credelio Quattro™ (lotilaner, moxidectin, praziquantel, and pyrantel), extending both products’ claims to include prevention of Lyme disease as a result of killing black-legged ticks (Ixodes scapularis) and treatment and control of longhorned tick (Haemaphysalis longicornis) infestations.
The update comes amid a sharp rise in tick-borne disease across the U.S. According to the Companion Animal Parasite Council (CAPC), more than 422,000 canine Lyme disease cases have been reported so far this year—surpassing the total annual cases seen in 2019. The Centers for Disease Control and Prevention (CDC) also reported the highest level of tick-related emergency room visits in humans since 2019.
“This label expansion is a testament to Elanco’s commitment to anticipating and addressing emerging parasite threats,” said Dr. Ellen de Brabander, Executive Vice President of Innovation and Regulatory Affairs at Elanco.
Expanded Protection Against Tick-Borne Threats
Both Credelio and Credelio Quattro use lotilaner, an isoxazoline active ingredient shown to rapidly kill black-legged ticks—the primary vector for Lyme disease. With the new label, both products are now officially indicated for the prevention of Lyme disease in dogs through the control of these ticks.
“With higher Lyme disease rates across much of the Northeast and Midwest, veterinarians now have more options to protect dogs,” said Dr. Casey Locklear, veterinarian and parasiticide lead for Elanco Animal Health. “Pet owners should ask about protection that includes Lyme prevention.”
The expanded label also adds protection against the longhorned tick, an invasive species now reported in 22 states. In peer-reviewed studies published in Parasites & Vectors, both Credelio and Credelio Quattro demonstrated 100% efficacy within 48 hours of infestation, maintaining full protection throughout the month.
“The longhorned tick can reproduce without mating, making population control difficult,” Dr. Locklear added. “That’s why broad-spectrum, sustained protection is critical.”
Both products were already approved to protect against the lone star tick (Amblyomma americanum), a species associated with alpha-gal syndrome (red meat allergy) in humans and multiple canine diseases.
“Rapid and sustained tick kill is key to preventing disease transmission,” said Dr. Kathryn Reif, Associate Professor of Parasitology at Auburn University. “Credelio products continue to deliver that level of performance.”
Information and quotes from company press release.
