Screwworm Has Reached a Texas Game Ranch. If Families Visit Your Livestock, Here's Your 5-Step Biosecurity Plan.

Oct 28

9 min read

Farmer at a cattle farm gate with a boot-wash and hand-wash station welcoming a family with two children at golden hour

A hunter in Pecos County, West Texas, brought down a female elk on a game ranch this October. Normal for hunting season. What came next was not. A sample from that elk tested positive for New World screwworm, and on October 21, 2026, USDA announced the first wildlife case of the current US outbreak.

If families pet, feed or walk past your animals, you don't need to panic or close. You need a written plan built on five habits: daily wound checks, smart timing of cuts and births, fly control, paperwork for every animal move, and fast reporting.

The short answer: Screwworm flies lay eggs in open wounds on warm-blooded animals. Check every animal the public can reach every day, keep wounded animals off display, and report anything suspicious to your vet and state animal health officials within 24 hours.

What Actually Happened in Texas and New Mexico

Texas Farm Bureau reports the sample tested positive at USDA's livestock insects lab in Kerrville. Because the elk was already dead when reported, the case counts as inactive.

The Texas Animal Health Commission (TAHC) is modifying an existing infested zone, and USDA and Texas Parks and Wildlife began extra wildlife surveillance.

Alan Cain, Wildlife Division Director at Texas Parks and Wildlife, put it simply: "We encourage all hunters and landowners to be vigilant for signs of New World screwworm..."

The same week, New Mexico confirmed screwworm in a beef cow near Piñon, in Otero County. Officials drew an infested zone reaching at least 12.4 miles from the cow. Animals inside it must be inspected, and treated if needed, before they move within or out of the zone.

USDA counted 59 animal cases in Texas and New Mexico as of October 21. By October 27 it was 66, including a sheep on the New Mexico State University campus in Las Cruces.

Timeline showing New World screwworm spreading north from Panama in 2023 to the first US wildlife case in Texas in October 2026 — Screwworm's march north: from Panama in 2023 to a Texas game ranch in October 2026.

This pest has been beaten before. It was wiped out of the US in the 1960s by releasing sterile male flies. Agriculture Secretary Brooke Rollins says more than 1.5 billion sterile flies have already been released in this fight, and she compared today's numbers with the 1972 outbreak, which saw more than 90,000 cases in Texas alone.

Serious, yes. But it is not 1972, and farms that act early have the edge.

Why a Farm With Visitors Has More to Lose

CDC says a wound as small as a tick bite can attract a female screwworm fly. She can lay 200 to 300 eggs at a time, and the maggots feed on living tissue.

TAHC warns that untreated animals "can die within one week of infestation."

Now picture that in a petting pen on a Saturday morning, with a school group walking in.

The real threat is bigger than one sick goat: a closed pen, movement restrictions, cancelled bookings and social media rumors, right on your busiest weekend.

Reality Check: Boot dips and hand sanitizer won't stop a fly. Screwworm travels on wings, on animals and on the wounds you miss. Your defense is eyes on every animal, every day. Keep your handwashing stations anyway, because they stop the germs that actually close petting zoos, as the Bengtson's E. coli case showed.

The good news? CDC rates the risk to people as very low. One travel-associated human case was confirmed in the US in August 2025, in a person returning from El Salvador. CDC reports no human case caught inside the US.

The 5-Step Screwworm Biosecurity Plan for Farms With Visitors

These five steps come from TAHC, Texas A&M AgriLife Extension, CDC and the national compendium public health vets use for animal exhibits, in the order a busy farm owner can follow.

Flowchart of a 5-step screwworm biosecurity plan for farms that host visitors — The 5-step plan: daily wound checks, cool-season timing, fly control, paperwork and fast reporting.

Step 1: Walk the Wound Line, Every Day

TAHC tells owners to check animals often for flies, maggots or eggs, especially around the nose, ears, navel and genitals. Look for drainage, foul smells or swelling.

Add the eyes, mouth and feet. Check newborn navels, and any animal you castrated, tagged or sheared, until fully healed.

Keep wounds clean and covered, with a treatment plan agreed with your vet in advance.

Field-Tested Play: Do your wound walk 30 minutes before opening, with a clipboard. Every animal visitors can touch gets a tick, and any animal with a wound leaves the public area before the gate opens. That log sheet is proof of your care if anyone asks.

Step 2: Move the Knife and the Births to Cool Months

Texas A&M AgriLife Extension advises scheduling castration, ear tagging, branding, dehorning, tail docking and shearing for the cooler, low-fly season.

They also suggest timing births for the cooler months. A new calf with a wet navel, sitting in your petting area in August, is exactly what this fly is looking for.

Walk your pens, chutes and petting fences for nails, wire ends and broken boards. Every scratch prevented is one less landing pad.

Step 3: Flies Off, Wounded Animals Off Show

Ask your vet which fly control fits your species. AgriLife lists permethrin sprays and permethrin ear tags as options. Coumaphos is a Restricted Use Pesticide, so you need a certified applicator license to use it. FDA keeps a current list of approved screwworm treatments.

The national compendium for animals in public settings is blunt: "Direct public contact with ill animals is inappropriate for any audience." It also tells venues to work with a licensed veterinarian.

So make it a rule: no wounded animal on display, ever. Keep a "rest pen" out of public view. See managing liability when hosting farm animals.

Step 4: Paper Every Move

In Texas, warm-blooded animals can't leave an infested zone without TAHC authorization. An authorized inspector checks them and issues an NWS Movement/Treatment certificate. It lists the product used and the animal's official ID, and it travels with the animal.

In New Mexico, animals inside a zone must be inspected and treated if needed before moving, and that includes pets.

Crossing state lines? Each state sets its own entry rules and a certificate of veterinary inspection is required, so check with the destination state first.

Step	What you do	How often	Backed by
1. Wound walk	Check navels, ears, nose, eyes, mouth, genitals, feet	Daily, before opening	TAHC, CDC
2. Cool-season timing	Castrate, tag, shear, dehorn and plan births in cooler months	Each season	Texas A&M AgriLife
3. Flies off, wounds off show	Vet-approved fly control; rest pen for any hurt animal	Daily	AgriLife, NASPHV Compendium
4. Paper every move	Zone check, inspection certificate, health papers, animal log	Every move	TAHC, NM Livestock Board
5. Report fast	Isolate, don't move, call vet and state officials	Within 24 hours	TAHC, AgriLife

Keep your own records too. The compendium tells venues to record where animals came from and when they moved. If you take animals to fairs or schools, see our guide to the USDA exhibitor license.

Step 5: Report in Hours, Not Days

TAHC asks owners to report suspected cases within 24 hours. AgriLife Extension says: "Do not delay reporting," even if you're not sure.

Isolate the animal, don't move it, and close that pen. Then call your vet and state animal health officials, and follow their instructions on larvae and treatment.

Decision flowchart showing what farm staff should do when they spot a wound on an animal visitors can reach — You spot a wound: the decision path to post in your barn, with Texas and New Mexico reporting numbers.

Texas: TAHC at 1-800-550-8242 (livestock and pets) or Texas Parks and Wildlife at 512-389-4505 (wildlife). New Mexico: Livestock Board at 505-841-6161. Elsewhere: your state veterinarian. Put these in your first aid and emergency plan so a weekend volunteer knows who to ring.

Make Your Visitors Part of the Plan

Your guests can help, straight from CDC and compendium advice:

Ask guests with open cuts or scrapes to keep them covered, as CDC advises.
Offer insect repellent at your entrance during warm months.
Keep visitor dogs out of animal areas. A dog has been among the cases. See protecting livestock from dogs for a pet policy that works.
Keep soap-and-water handwashing at every exit. The compendium prefers it to sanitizer.
Supervise children under 5 at all times in animal areas.

Field-Tested Play: Give staff one calm line for "Is it safe?": "We check every animal every morning, and any animal with a scratch rests out of sight until it heals." Parents trust a system. See how to train farm staff for great customer service.

Questions to Ask Your Vet, State Veterinarian and Insurer

I'm not your lawyer, vet or insurance agent, so walk in with a written list. Here's mine.

Ask your vet: Which fly control and wound products suit my species? Can we write a herd health plan together? What should my staff collect if they find larvae?

Ask your state veterinarian: Is my farm inside or near an infested zone today? What do I need before taking animals to a fair, school or another farm?

Ask your insurer: Does my policy cover lost income if officials restrict my animals or I must close an area? Are animal deaths from disease covered? Does my liability cover still apply if a visitor claims an animal made them sick?

Get the answers in writing, then compare them with our guides to petting zoo insurance, agritourism insurance coverage, Texas agritourism insurance and your state's agritourism liability law.

Reality Check: An insurance policy that says nothing about disease or government orders is not the same as one that covers them. Silence is a question, not an answer. Ask.

A Note From My Own Farm

At Bloopy Durians in Bentong, Malaysia, we keep chickens, geese, ducks and fish, and we welcome visitors from all over the world. Different country, different pests, same lesson: guests trust you with their children, and that trust is your real product.

Frequently Asked Questions

Can people catch screwworm at my farm?

CDC rates the risk to people as very low. No human case acquired inside the US has been reported. CDC still advises keeping any open wound clean and covered and using an EPA-registered repellent outdoors.

Should I close my petting zoo?

Not over headlines alone. If you're in an infested zone or find a suspected case, follow your state officials' instructions.

Which animals can get screwworm?

Warm-blooded animals: mainly livestock, plus pets, wildlife and sometimes birds. US cases so far include cattle, horses, sheep, a dog and now an elk.

Does cold weather end the risk?

No. New Mexico's Agriculture Secretary Jeff Witte said: "Cold daytime temperatures can slow screwworm activity, but the risk is not completely eliminated." AgriLife notes adult flies have limited activity below 59°F.

What if a visitor finds maggots on their own skin?

Tell them to see a doctor right away and not to remove the maggots themselves, as CDC advises. Record it in your incident log.

I farm in Canada or the UK. Does this matter to me?

This outbreak is in the Americas, from Panama up to Texas and New Mexico. The five habits still protect any farm with visitors. Ask your vet what applies where you are.

Your Next Step

A profitable season is planned before the first car turns in. Insurance questions, an emergency plan and a bad-weather policy all belong on paper first.

That's what The First-Season Profit Plan walks you through: a 39-page workbook with 6 printable worksheets, the 12-Week Countdown, the Opening Day Scorecard, the Busiest-Hour Calculator and 8 questions to ask your insurer before you build anything. Instant PDF download, $37, with a 30-day money-back guarantee.

Get The First-Season Profit Plan ($37)

Not sure your farm is ready for visitors? Take the free quiz and find your weak spots.

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P.S. One hunter checked one elk, and an entire state learned the parasite had reached its wildlife. On your farm, you are that hunter. Ten minutes of looking every morning could be the difference between a quiet note in your log and a closed gate in your best month.

By Stephen Loke of AgritourismSuccess.com, whose farm is featured in Bloomberg News and Asahi Shimbun. This article is general information, not veterinary, legal or insurance advice. Rules change quickly during an outbreak, so check with your vet, your state veterinarian and your insurer before acting.