Recent headlines about the New World screwworm have understandably raised questions among pet owners. With information circulating in news reports and on social media, it can be difficult to know what this parasite means for your dog or cat and how concerned you should be.
Our veterinary team at Stonebridge Veterinary Wellness wants to help you separate the facts from the worry. The New World screwworm is a parasitic fly that can affect pets when its larvae infest an open wound or other vulnerable area. While the risk to most pets remains low, knowing what to watch for and when to contact your veterinarian can help you respond quickly if concerns arise.
Understanding the New World Screwworm
The New World screwworm, scientifically known as Cochliomyia hominivorax, is a fly whose larvae cause a condition called myiasis, or fly larvae infestation. Adult flies lay eggs in open wounds or, less commonly, on healthy skin near the eyes, ears, or nose, and the larvae then burrow into living tissue, causing wounds to deepen and attract even more flies. According to the Centers for Disease Control and Prevention, pets and people face increased risk in areas where these flies have infested other pets, particularly those with open wounds or skin conditions.
The New World screwworm was considered eradicated from the United States decades ago and has since remained contained to parts of Mexico and Central America. Cases have recently been confirmed in the southwestern United States, including in dogs, which explains why so much information, some accurate and some not, has circulated online. The current risk outside those areas remains low.
Signs of Myiasis in Dogs and Cats
Recognizing the signs of myiasis early can make a meaningful difference in how quickly it can be treated. Screwworm larvae burrow deep into tissue, so they are not always visible, which makes other symptoms important to watch for. Signs that may indicate a fly larvae infestation include:
- A foul odor coming from a wound or affected area
- A wound that is swollen, leaking fluid, or rapidly enlarging
- Visible maggots or eggs in a wound or near the eyes, nose, ears, mouth, or anus
- A pet who seems unusually restless, withdrawn, or reluctant to eat
If your pet has recently traveled to or returned from an affected area and has any wound, please contact us right away, even if the wound seems minor. The same goes if you notice any of the signs above.
How Pets Become Infected and How Myiasis Is Treated
Infestation happens when a fly lays eggs on a pet’s skin or mucous membranes, often in moist or wounded areas. Pets who spend time outdoors face a somewhat higher risk, and older pets may also face added risk, because slower healing can make wounds linger. This is one reason our senior pet care visits include a close look at skin health.
Treatment focuses on removing every larva and supporting the wound as it heals. Our team thoroughly cleans affected wounds, removes damaged tissue, and may recommend parasite medications or antibiotics depending on severity.
Steps to Help Protect Your Pet
One of the most helpful things you can do is pay attention to your pet’s skin and address wounds promptly. Keep cuts and healing areas clean, check them regularly for changes, and contact your veterinarian if you notice unusual drainage, worsening irritation, or signs that the area is not healing normally. Routine preventative care also gives your veterinary team an opportunity to identify skin or health concerns that may need attention.
Travel may require some additional precautions, particularly if you are visiting an area where New World screwworm has been reported. Check current pet travel requirements before you leave and continue monitoring your pet for wounds or unusual skin changes during your trip. Screwworm does not spread directly from an affected pet to another pet or person, but an infestation can indicate that the flies are present in the area.
What to Do If You Are Concerned About Your Pet
If something about your pet’s skin or a wound concerns you, start by taking a closer look at the area and noting any changes you have noticed. Most wounds and skin changes are not caused by New World screwworm, but anything that looks unusual, worsens, or does not seem to be healing normally is worth discussing with your veterinarian. Our team can help you determine what may be happening and whether your pet needs an examination.
Online information can make it difficult to separate reasonable precautions from unnecessary worry. Stonebridge Veterinary Wellness keeps complimentary New World screwworm information sheets available for pet owners who want reliable information to keep on hand or share with family members.
Reach Out to Stonebridge Veterinary Wellness With Any Concerns
Knowing what to watch for can make New World screwworm concerns feel a little less uncertain, especially as new information continues to circulate. If you notice larvae in a wound or another concerning change in your pet’s skin, our urgent care team can evaluate the area and determine what treatment may be needed. You can also pick up one of our complimentary information sheets if you would like a reliable resource to keep at home.
You do not have to determine what is causing a wound or skin change on your own. If something does not look right or you have questions about your pet’s risk, please contact us so our team can help you decide what to do next.
