06/07/2026
๐๐๐ ๐๐๐ฌ ๐๐ค๐ง๐ก๐ ๐๐๐ง๐๐ฌ๐ฌ๐ค๐ง๐ขโฆ๐ผ๐ฃ๐ ๐๐๐ ๐ฟ๐ค๐๐จ ๐๐๐๐ฉ ๐๐๐ก๐ฅ๐๐ ๐๐๐ฃ๐ ๐๐ฉ
One of the more interesting rabbit holes I have gone down this week while learning more about New World Screwworm has honestly had very little to do with flies and a whole lot more to do with dogs.
And before somebody laughs and says, โYouโre telling me ranch dogs were out there smelling screwworm cattle?โ Wellโฆmaybe.
After my last post, a gentleman from South Texas commented something that caught my attention. He talked about how, years ago in South Texas brush country, dogs were sometimes used to help locate cattle that had laid up in the brush with screwworm infestations. Not as some polished government program or anything formal, but simply as practical ranching on outfits that had figured out what worked.
And frankly, the more I have thought about it, the more sense it makes.
One thing folks need to understand about screwworm is that cattle do not always stand out in the middle of a pasture waving a flag that says, โHey, somethingโs wrong with me.โ A calf with a bad navel infestation, a cow with an infected wound, or an animal that is simply miserable from pain and flies will often drift off, bed down in shade, tuck itself into brush, and quit traveling with the herd. In thick country, especially the kind of mesquite, cactus, cedar, and brush they have in South Texas, finding one sick animal can become a needle-in-a-haystack situation real fast.
That is where these stories about dogs start to get interesting.
Several folks have now mentioned dogs learning to find laid-up cattle with screwworms, likely by smell. And biologically, that is not nearly as far-fetched as some might think. Screwworm wounds are not subtle. The larvae feed on living tissue, wounds drain, infection often sets in, and there is a very distinct smell that comes with tissue breakdown and infestation. Frankly, if a human can smell it, I have a hard time believing a good dog cannot.
Now, to be fair, I have not found much formal documentation from the โold daysโ showing organized screwworm dog programs on ranches. But letโs be honest hereโฆcowboys were not exactly out writing peer-reviewed journals after gathering cattle all day either. A whole lot of ranch knowledge got passed around over tailgates, branding fires, coffee cups, and horseback conversations, not textbooks.
What I did find interesting is that there actually has been research showing dogs can detect screwworm. Scientists successfully trained detector dogs to identify screwworm pupae decades ago, and today USDA and Mexico are actively using detector dogs as part of surveillance and biosecurity efforts. So maybe those old cowboys in South Texas were onto something long before anybody put a study behind it.
Honestly, it sounds a whole lot like good stockmanship to me. Good horses. Good dogs. Paying attention. Knowing your country and your cattle well enough to notice when something ainโt right.
And if I had to guess? I doubt these were soft little house dogs. I imagine gritty cur dogs, Catahoulas, rough stock dogs, or brush dogs with enough sense to pressure cattle out of cover without putting more cuts and abrasions on them, because with screwworm every scrape matters.
Funny how every time agriculture runs into an old problem, we end up rediscovering old tools.
Maybe the lesson in all of this is that modern technology matters. Science matters. USDA surveillance matters.
But so does old cowboy knowledge.
๐ญ ๐ค๐๐ฒ๐๐๐ถ๐ผ๐ป ๐๐ผ๐ฟ ๐ฌ๐ผ๐
For my ranchers, hunters, and old brush-country folksโฆhad you ever heard of dogs being used to help locate screwworm cattle? And if so, what kind of dogs were they using? ๐
โ ๐๐ซ๐ซ๐จ๐ฐ ๐ ๐๐๐ญ๐ญ๐ฅ๐ ๐๐จ.
๐๐ณ๐ฐ๐ฎ ๐ต๐ฉ๐ฆ ๐๐ช๐จ๐ฉ ๐๐ญ๐ข๐ช๐ฏ๐ด ๐ต๐ฐ ๐บ๐ฐ๐ถ๐ณ ๐ฑ๐ญ๐ข๐ต๐ฆ.
๐๐ค๐ช๐ง๐๐๐จ
โข Animal and Plant Health Inspection Service (APHIS), U.S. Department of Agriculture. โNew World Screwworm Prevention, Detection, and Response.โ Accessed June 5, 2026.
โข Animal and Plant Health Inspection Service (APHIS), U.S. Department of Agriculture. โUSDA Confirms Presence of New World Screwworm in the United States.โ June 2026.
โข Texas Animal Health Commission. โNew World Screwworm Information and Producer Guidance.โ Accessed June 5, 2026.
โข Texas A&M AgriLife Extension. โNew World Screwworm: Identification, Risks, and Livestock Management Considerations.โ Accessed June 5, 2026.
โข Welch, J.B., et al. โUse of a Detector Dog for Screwworm Surveillance.โ Journal of Economic Entomology, 1990.
โข Reuters. โDetector Dogs Help Mexico Fight Flesh-Eating Screwworm.โ 2025.
โข Rancher and cowboy firsthand accounts from South Texas brush country regarding historical working-dog use for locating laid-up cattle with suspected screwworm infestations. (Anecdotal historical accounts; limited formal published documentation available.)
