New World Screwworm is officially confirmed in the U.S. after it made its way over the border from Mexico. Now that it is in the U.S. cattle herd, we have also seen our first case of NWS in a different mammal- a dog in New Mexico. It is not a surprise, as NWS is not picky, but it proves that all animal owners need to be cautious about this pest. Dr. Lisa Becton, associate director of the Swine Health Information Center (SHIC), said tracking and monitoring emerging diseases and pests allows for mitigation plans to be made.
“If we understand what they are, where they’re happening, then we can come up with mitigations and reduce the impact to producers. So that’s really our focus and our mission. So, you’re right, with New World screwworm being identified, we were actually monitoring this back in 2024 when we started to see it come into Mexico. So, we have resources available, such as a webinar that outlines what this parasite is, what it looks like, where it’s at, what USDA is doing. They get into more detail of what this sterile insect technique is. But also, we’ve got other resources, like fact sheets. So, we have a brand-new fact sheet on New World screwworm that outlines specifically for pork producers what this disease is, what it looks like, what producers should do if they suspect a case. So really our goal is to help inform people so they can be aware, alert and monitor for it as well.”
Dr. Becton said female NWS flies look for any open wounds on warm-blooded mammals to lay their eggs in.
“New World screwworm really impacts all mammals. And so, when the female lays her eggs, she targets any kind of wound. So, you know, as all mammals, they’re warm-blooded. And so, when the female lays her eggs, she doesn’t really worry about what species it is. So, pigs can be impacted, cattle can be impacted. And so, yes, it’s an important disease for all animals because it creates very painful wounds for animals. It reduces production impact, and it can spread to other animals. So, it’s not a good disease to have. And it’s something that I know a lot of producers are concerned about, and USDA is really working to eradicate it back from the U.S.”
The frequent transportation of livestock across the country means that even producers in other states further north need to be vigilant for symptoms of an NWS infection. Dr. Becton said SHIC offers regular disease monitoring out of places like Iowa State University, which provides livestock producers with a detailed tool to track NWS movement.
“While this is occurring in Texas, you think, OK, how does this affect me as someone in Iowa? Well, it’s not just the flies that move, but we have people that move. We have other animals, whether it’s cattle, sheep, hogs or goats. And so, it’s always important to be aware of what are the diseases in your area. And you can do that, obviously, through USDA’s website for screwworm. But for Schick, we offer other things, such as regular disease monitoring out of Iowa State University. And so that helps people understand things like PERS and PED. And you can even pinpoint it down by state. So again, if you’re aware and understand what’s happening in your area, then you can make your own herd health decisions. Do you wean pigs into this particular area where a lot of PERS is active, or do you wait and go somewhere else? So just being informed helps you make better decisions on how to protect your health and protect your operation.”
Dr. Becton said they also offer monthly reports and summaries that producers can sign up to receive.
“We do offer a lot of these reports on a once-a-month basis through our Schick monthly newsletter. And so that outlines a summary of what is going on each and every month. But then if you want to go do a deeper dive, you can go into the specific reports, and it’ll show you different things, like what are the diagnostics by age, you know, where in the state is or where in the country is a disease occurring. So, there’s a lot of deeper dives you can do, but we do provide a summary of here’s what’s happening this month, here’s what you should be about and why it’s important.”
As a reminder, NWS causes an infestation, not a disease. There is still no risk to the food supply. For more information, visit swinehealth.org.