New World Screwworm Pet Safety: What Owners Should Watch

Pet owners in affected areas are being warned to check wounds closely as New World screwworm returns to the U.S. animal-health map.

The CDC’s New World screwworm overview says the fly lays eggs on open wounds or body openings in living warm-blooded animals, and wounds as small as a tick bite can attract egg-laying females.

The national pet risk remains low, but not zero

CDC’s situation summary says the current risk to the public and animals in the U.S. is very low.

That national message does not mean every pet has the same risk.

Animals recently in areas with confirmed cases face higher concern, especially if they have wounds, skin lesions, tick bites, surgical sites or access to outdoor areas where flies can reach them.

USDA-APHIS said most dogs and cats in the U.S. remain low risk when it announced an emergency use authorization for generic nitenpyram tablets to treat New World screwworm infestations in dogs, puppies, cats and kittens that meet age and weight requirements.

That treatment authorization gives veterinarians another tool, but it does not replace wound checks or reporting.

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The warning signs are wound-focused

New World screwworm is not a typical nuisance fly problem.

The larvae feed on living tissue, which makes early detection critical.

USDA’s prevention page says wounds can become larger and deeper as more maggots hatch and feed.

CDC’s clinical overview says patients may have a rapidly worsening, foul-smelling wound with significant pain and may see or feel larvae moving.

For pets, owners should watch for wounds that expand quickly, smell bad, bleed, drain fluid, attract flies, show visible larvae or cause unusual pain, licking, restlessness or hiding.

Any of those signs near a confirmed-case area should trigger a veterinarian call.

Dogs and cats can be exposed through tiny openings

Pet owners often think only large cuts matter.

CDC says a female fly can be attracted to body openings such as the nose, mouth, eyes, ears or genitals, as well as wounds.

That makes outdoor dogs, working dogs, hunting dogs, livestock-guarding dogs, feral cats, recently rescued animals and pets recovering from surgery more important to monitor.

Ticks, scratches, bite wounds and healing surgical sites should be cleaned and covered when possible.

Owners should not try to remove deep larvae at home if screwworm is suspected. Veterinary handling is safer because animals may need wound cleaning, larval removal, pain control, antibiotics and officially recommended treatment.

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Texas reporting rules make speed important

The Texas Animal Health Commission’s New World screwworm page says affected animals should be treated immediately and that a veterinary-client relationship is critical to effective treatment.

TAHC also says New World screwworm is reportable.

The agency’s pest reporting page tells owners to contact a private veterinarian or a TAHC region office if they suspect or confirm a case.

That reporting step matters because screwworm control depends on location.

Officials need to know where the infestation is, what animal was affected, whether more animals were exposed and whether fly-control measures should be expanded.

Treatment options are expanding

The FDA has used emergency and conditional pathways to make more animal treatments available.

APHIS said the FDA issued an emergency use authorization for generic nitenpyram tablets for dogs and cats in June 2026.

APHIS also said the FDA had conditionally approved Credelio Quattro-CA1 for treatment of New World screwworm larvae infestations in dogs and puppies meeting age and weight requirements.

These products should be used through veterinary direction.

Pet owners should not assume every flea or tick medicine treats screwworm, and they should not apply livestock treatments to dogs or cats unless a veterinarian directs it.

The household checklist is simple

Owners in affected or nearby areas should inspect pets daily for wounds, especially after outdoor activity.

Check ears, eyes, paws, tail base, genitals, surgical sites and any area the pet keeps licking.

Keep wounds clean and covered when practical, reduce fly exposure, maintain parasite prevention recommended by a veterinarian and avoid moving animals with suspicious wounds before contacting a professional.

For travel, pet owners should check local animal-health alerts before moving dogs or cats from affected regions.

Shelters, rescues and boarding facilities should be especially careful with intake exams because they may see animals with unknown wound histories.

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