| Topic | Key Detail |
|---|---|
| Product | F10 Antiseptic Wound Spray with Insecticide |
| Active Ingredients | Benzalkonium chloride, polyhexanide, cypermethrin |
| Authorization | FDA Emergency Use Authorization (EUA) - March 10, 2026 |
| Authorized Indication | Expanded on June 22, 2026, to cover prevention and treatment of NWS myiasis. |
| Approved Species | Cattle, horses, minor hoof stock, raptors, wild and pet birds, captive wild, exotic, and zoo mammals. |
F10 Antiseptic Wound Spray with Insecticide is the first FDA-authorized product for the prevention and treatment of New World screwworm (myiasis) in certain animal species under an Emergency Use Authorization (EUA). The authorization follows the resurgence of New World screwworm symptoms (NWS), a destructive parasite that has raised concerns among veterinarians, livestock owners, and wildlife caretakers. F10 is intended only for animal species authorized under the FDA EUA.
Understanding New World screwworm
New World screwworm, scientifically known as Cochliomyia hominivorax, is a parasitic fly that poses a serious risk to warm-blooded animals. Unlike many flies that are drawn to decaying matter, NWS flies feed on healthy living tissue, making them particularly destructive.
Key characteristics of this parasite include:
- Egg-laying behavior : Female NWS flies lay their eggs in and around open wounds and mucous membranes of animals.
- Larval feeding pattern : Once hatched, the larvae, commonly referred to as maggots, burrow into the flesh of the host animal and consume healthy, living tissue rather than dead tissue.
- Medical term for infestation : This condition is clinically known as myiasis, and when caused by NWS, it results in a severe and progressively damaging screwworm-infested wound.
- Affected species : NWS can infest livestock, pets, wildlife, and occasionally birds. In rare instances, it can also affect humans.
- Severity of damage : The larvae infest the deepest layers of living tissue, including the skin and sensitive bodily cavities such as the ocular, oral, nasal, and genital regions.
The Life Cycle of the Screwworm Fly
Understanding the reproductive cycle of NWS helps explain why prompt identification and treatment of a New World screwworm wound is so critical:
Under favorable conditions, female NWS flies mate three days after emerging, begin laying eggs two days later, and may live over 30 days. Under such conditions, the average life cycle of the Screwworm (GBG) is approximately 21 days.
This rapid reproductive timeline underscores the importance of early intervention, as delays in treatment can allow the infestation to expand quickly within a wound and increase the risk of reinfestation.
Identifying Screwworm Flies
Proper identification is essential, as NWS closely resembles a related, non-harmful species. Distinguishing features include:
- New World screwworm (Cochliomyia hominivorax) : A metallic blue blow fly with three distinct stripes running down the top of the thorax, positioned just behind the head, and featuring large orange eyes.
- Secondary screwworm (Cochliomyia macellaria) : Also a metallic blue blow fly with three stripes; however, all three stripes begin at the same point behind the head. Importantly, this species does not lay eggs on living animals, and its larvae do not infest living tissue, meaning it does not infest healthy living tissue.
Because visually distinguishing NWS larvae from those of other myiasis-causing flies is difficult, veterinary guidance is strongly recommended when a screwworm wound treatment is being considered.
The FDA Authorization Timeline
On March 10, 2026, the FDA issued an Emergency Use Authorization (EUA) for F10 Antiseptic Wound Spray with Insecticide - a topical solution of benzalkonium chloride, polyhexanide, and cypermethrin. F10 Antiseptic Wound Spray with Insecticide is the first product authorized by the FDA for NWS indications in additional species.
On June 22, 2026, the FDA revised the authorized indication to include the prevention and treatment of infestations caused by New World screwworm infection larvae (myiasis in cattle, horses, minor species of hoof stock, raptors and other wild birds, pet captive wild, exotic, and zoo mammals.
Which Animals Can Be Treated With F10 Antiseptic Wound Spray with Insecticide?
F10 Antiseptic Wound Spray with Insecticide is authorized for use in the following species:
- Cattle
- Horses
- Minor species of hoof stock (e.g., sheep, goats, deer)
- Raptors and other wild birds
- Pet birds
- Captive and captured wild, exotic, and zoo mammals
Important note : This product is not authorized for use in domestic dogs and cats under the current FDA Emergency Use Authorization (EUA).
Product Composition and Description
F10 Antiseptic Wound Spray with Insecticide is an amber-colored topical spray with a slight alcohol odor. Its active ingredients include:
- Benzalkonium chloride - 0.405 g/100 mL
- Polyhexanide - 0.03 g/100 mL
- Cypermethrin - 0.25 g/100 g
The product is indicated for use as a topical antiseptic for surface wounds, to repel flies, and to treat infestations resulting from fly strike in raptors, pet birds, captive small mammals, captive reptiles, and captive exotic or zoo mammals.
Directions for Use
Proper application is essential for both safety and effectiveness in infected animal wounds.
Recommended directions include:
- Use disposable gloves during application, and wash hands thoroughly afterward.
- Apply only in well-ventilated areas.
- Clean the wound thoroughly prior to application.
- Apply a maximum of five applications per animal for animals with multiple wounds (one to two sprays per wound).
- Hold the spray 4 to 8 inches away from the wound to ensure full coverage.
- Spray only the wound site and avoid unnecessary application to surrounding areas.
- Repeat treatment once a week, if necessary, or as advised by a veterinarian.
- Because the product is water soluble, it should be reapplied if the animal is bathed or exposed to rain.
- If the wound persists or worsens, contact a veterinarian promptly.
Following these steps carefully is critical to effectively managing a New World screwworm wound.
Important Food Safety Considerations
Because several of the approved species are used for food production, the FDA has outlined specific withdrawal periods to protect the food supply:
- Cattle, goats, and sheep must not be slaughtered for human consumption within 30 days of treatment.
- Non-domesticated minor hoof stock (e.g., deer, elk, antelope, and nilgai) should only be treated when there is reasonable certainty the animal will not be slaughtered or harvested for human consumption within 30 days.
- Milk from treated cows, goats, or sheep must not be used for human consumption during treatment and for 10 days after treatment concludes.
- A withdrawal period has not been established for pre-ruminating calves. Treated calves, as well as calves born to treated cows, must not be processed for veal.
These guidelines are essential for producers and caretakers to follow in order to remain compliant with food safety standards while treating a New World screwworm wound.
Final Thoughts
The FDA's authorization of F10 Antiseptic Wound Spray with Insecticide provides veterinarians, livestock producers, and wildlife caretakers with an important resource for managing the threat posed by New World screwworm. Given the severity and rapid progression associated with a New World screwworm wound, prompt recognition, careful treatment, and adherence to food safety withdrawal periods are essential.
As with any veterinary treatment, caretakers should consult a licensed veterinarian to determine the most appropriate course of action for their animals, ensuring both effective treatment and full regulatory compliance.
Follow the product labeling and veterinary guidance whenever using FDA-authorized treatments.
