The FDA has conditionally approved Merck Animal Health’s EXZOLT CATTLE-CA1, a prescription fluralaner topical solution for preventing and treating New World screwworm larvae infestation in cattle. Conditional approval is not the same as full approval, and Merck’s earlier launch forecast does not confirm current availability.
What the FDA conditionally approved
EXZOLT CATTLE-CA1 is a topical solution containing fluralaner. The FDA’s New World screwworm drug overview lists it as conditionally approved for prevention and treatment of myiasis caused by New World screwworm larvae in cattle. Merck’s December 4, 2025 announcement also describes an indication for treatment and control of cattle fever tick.
What New World screwworm does to animals
New World screwworm is the fly Cochliomyia hominivorax. It lays eggs in or on open wounds and mucous membranes. The larvae burrow into flesh and feed on living tissue, and the infestation can be serious and often deadly to animals, according to the FDA.
What “conditional approval” means here
The FDA’s regulatory overview distinguishes conditional approvals from Emergency Use Authorizations (EUAs); they are separate mechanisms, not interchangeable labels. The agency’s overview, current as of September 3, 2026, lists three conditional approvals and 15 EUAs for animal drugs against New World screwworm. Its veterinarian information page explains that the FDA is working with sponsors and provides information on conditional approval, EUA, and extra-label use.
#1 Best Overall
- Broad-Spectrum Deworming: This 5 mg/mL Modectin Solution helps control multiple parasites in livestock, supporting healthy growth, comfort, and overall well-being
- Dung Beetle & Environment Friendly: Helps support pasture health and soil quality while promoting a balanced grazing environment for livestock
- Multiple Benefits: This dewormer Liquid helps support healthier digestion, improved nutrient absorption, and helps animals regain natural energy and vitality
The sources cited here do not establish a product-specific efficacy percentage, trial sample size, or basis for comparing EXZOLT CATTLE-CA1’s efficacy with other products. Regulatory status and labeled indications can be compared, but they do not by themselves show which product works better.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Availability and how to ask about it
Merck described EXZOLT CATTLE-CA1 as prescription-only and offered in 1 L and 5 L presentations. Its December 2025 announcement projected availability in the first quarter of 2026; that forecast does not verify present stock. Ask a veterinarian or authorized animal-health seller about current availability and appropriate use. The cited sources do not verify Amazon listings or other online stock.
Quick Recap
Best Value
- Multi-species deformer
- This product is easy to Use
- This product is manufactured in China
- Brand name: Animal Health International
Rank #4
- Fast & Effective Parasite Control: Our 10% fenbendazole dewormer liquid rapidly targets stomach worms, lungworms, hookworms, nodular worms, roundworms, and pinworms, helping your animals regain appetite, energy, and vitality
- Safe for All Animals: Formulated for mixed farms and multi-pet households, this fenbendazole dewormer works safely for goats, sheep, horses, cattle, dogs, cats, chickens, rabbits, and other livestock—no more juggling multiple dewormers
- Veterinarian-Trusted Formula: Fenbendazole is widely used and well-studied. Unlike ivermectin, which mainly paralyzes worms, fenbendazole delivers thorough, lasting parasite control while remaining gentle on your animals’ digestion
- Gentle Yet Powerful: The non-irritating fenbendazole formula suits animals of all ages and sizes, supporting a healthy internal balance and overall wellness. Effective yet easy on digestion, goat dewormer helps your animals feel good from the inside out
- Convenient & Mess-Free Dosing: No more deworming struggles. The 100 mL fenbendazole liquid allows precise measuring, oral drenching, or easy mixing with feed—combining feeding and treatment in one simple step. Ideal for picky or hard-to-dose animal
Rank #3
- Ready-to-use dust for direct application on animals, poultry and bedding
- Controls face flies, horn flies, northern fowl mites, lice, fleas and ticks
- For use on beef cattle, dairy cattle, horses, swine, poultry, dogs and cats
- See label for complete usage instructions by species treated.
- Apply direct to animals, poultry and bedding.
Rank #2
- Dewormer for Beef & Dairy Cattle and Goats, 33.8 fl oz (1000 mL)
- Storage And Handling: Store at or below 25°C (77°F). Protect from freezing.Shake well before use.
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