Early February, a horse imported to Florida from Argentina arrived with New World screwworm (NWS). It was the first of the pest to reach the United States during this worldwide outbreak, meaning a lot of agriculturists are being more cautious than ever before. 

“I think a lot of us in the industry have not really faced [something like this] in our lifetime,” says Mark Alley, Zoetis managing veterinarian. 

But it’s not all bad news on the topic. Alley says it’s important to remember our nation has faced this threat before. In past years, NWS outbreaks were handled with the release of sterile flies. 

This year, however, Alley says it’s vital for producers to stay diligent and informed to help manage potential risk. He and Deana Hardee, veterinarian on Merck’s cattle sales team, offer the following advice. 

1. Understand the threat. 

Hardee reminds cattlemen the NWS is a fly, so as we enter a more prominent fly season, it’s more important than ever to have a pest management and biosecurity plan in place. 

When looking at potential infection, Hardee warns that larvae or an egg pack can be laid deep in a wound. While hard to spot, she says there is a distinct smell that comes with the screwworm, so using more than just the sense of sight is important. 

Cattle tend to be a breeder’s first concern, but Alley says screwworms can infect a variety of hosts. Other livestock, wildlife, and even humans can be infected. 

2. Monitor infection sites. 

While the first goal is to prevent injury in livestock, Alley says, “Anything that is an open wound has the potential for [the flies] to be drawn to.” 

That means anything as small as a needle prick or tick bite can be an infection site. 

Hardee reminds producers some production practices can also create the perfect spot for the NWS to land.  Branding, castration and dehorning are a few examples. 

“We are wanting people to think about those stress points and their processing systems that may create that open wound,” she says. 

Other, more natural parts of livestock management also can pose a threat. Alley says watch any areas with a mucus membrane for their ability to serve as an infection site. 

Umbilical cords or genital infections postcalving need extra attention from producers. 

3. Work with a veterinarian. 

“I can’t encourage enough using a local veterinarian,” Hardee says, recommending all cattlemen have a VCPR — a veterinary client patient relationship. “That doesn’t necessarily mean they have to be on your ranch monthly. That just means they know what’s going on at your operation. They’re comfortable with your practices, how you do things…” 

A vet can help implement a whole-herd parasite control program, a practice Alley stresses as vital. Internal parasites, flying insects and lice are just a few examples of pests that should be monitored year-round. 

Having a vet involved not allows them to prescribe mediation when needed, but can also help make reporting concerns of a screwworm infestation simpler.