What Is the New World Screwworm Fly?
The New World screwworm fly (Cochliomyia hominivorax) is a parasitic insect whose larvae infest open wounds in warm-blooded animals, including pets. The fly lays eggs on wounds, and the hatching maggots feed on living tissue, causing severe damage and potentially death if untreated. According to the USDA, infestations can kill an animal within 7 to 14 days.
How Pets Get Infested
Pets become infested when adult female flies lay eggs on cuts, scratches, or even tick bites. The larvae burrow into the wound, causing pain, swelling, and secondary infections. Dogs and cats are particularly vulnerable, especially those with outdoor access or untreated wounds.
Signs of Screwworm Infestation
Early symptoms include restlessness, licking or scratching at a wound, and a foul odor. Visible maggots in the wound are a definitive sign. Infested animals may also show signs of depression, fever, and loss of appetite.
Prevention Tips for Pet Owners
To protect your pets, inspect them daily for wounds, especially if they spend time outdoors. Keep any cuts clean and covered. Use veterinarian-recommended insect repellents and avoid leaving pets unsupervised in areas with high fly populations. The USDA recommends prompt treatment of any wound and maintaining good hygiene.
Treatment Options
If you suspect screwworm infestation, seek veterinary care immediately. Treatment involves removing larvae, cleaning the wound, and applying topical insecticides. In severe cases, surgery may be required. Antibiotics are often needed to prevent secondary infections. Early intervention is critical to survival.
What to Do If You Suspect Infestation
Contact your veterinarian or local animal health authority. In the U.S., report suspected cases to the USDA’s Animal and Plant Health Inspection Service. Do not attempt to remove larvae yourself, as this can worsen the wound.
Additional Resources
For more information, visit the USDA website or consult your veterinarian. The American Veterinary Medical Association also provides guidelines on preventing screwworm infestations in pets.
