In today’s Beef Buzz, senior farm and ranch broadcaster Ron Hays speaks with John Hutcheson, with Merck Animal Health, who discusses a newly available product designed to help cattle producers combat the threat of New World Screwworm. The prescription pour-on product, Exzolt Cattle CA1, offers both treatment and prevention against screwworm infestations, giving producers another tool as the industry prepares for potential outbreaks.
Hays noted that producers today have more options than ranchers did during the major screwworm battles of the 1950s and 1960s. Hutcheson said Merck is excited to bring new technology to the cattle industry at a critical time.
“We have a new product that’s been on the market since the advent of both New World Screwworm impeding coming to the United States,” Hutcheson said. “It’s called Exzolt Cattle CA1, it’s a pour-on, and the most exciting part about it is it’s the first and only topical product that can be used for either prevention or treatment of New World Screwworms.”
New Drug Class Offers Prevention and Treatment
According to Hutcheson, the product also represents a major scientific advancement because it belongs to an entirely new class of parasite control products approved for U.S. cattle. “It’s the first isoxazoline class ectoparasiticide that’s approved in the U.S.,” Hutcheson said. “It’s a new drug class that offers producers some prevention and treatment, and so it’s pretty exciting to be able to provide a tool that’s new and a technology that’s new to help fight this battle.”
He emphasized that the cattle industry has defeated screwworm before and now has better tools to help prevent another widespread outbreak.
Veterinarians Critical to Screwworm Response
Because Exzolt Cattle CA1 is a prescription-only product, Hutcheson stressed that producers need to work closely with their veterinarians. “It’s a vet prescription product only,” Hutcheson said. “You will have to make sure you have a veterinary patient-client relationship.”
He said veterinarians are essential not just for prescribing the product, but also for helping ranchers manage risk and identify problems early. “They know what’s going on in your geography, they know what’s going on in other ranches,” Hutcheson said. “They can help guide you with management practices that can help lower the fly risk.”
Hutcheson pointed to the recent Texas screwworm case, where a private veterinarian identified the infection and initiated the reporting chain to state and federal animal health officials. “I can’t express how important it is to get a veterinarian involved,” he said. “They’re usually at the tip of the spear and know what’s going on in your geography.”
Strong Results in Prevention and Treatment Studies
Hutcheson said Merck’s research showed impressive results when Exzolt Cattle CA1 was used during procedures that create open wounds, such as castration. “We poured the product on at the recommended dose and followed those animals,” Hutcheson said. “They were exposed to New World Screwworms, and we had 100% prevention of myiasis over a 14-week timeframe.”
He explained that myiasis occurs when screwworm larvae begin feeding on living tissue, causing wounds to rapidly worsen. “That’s what happens when the maggots start eating the living tissue in the animals and creating that wound that gets bigger and bigger and bigger,” Hutcheson explained.
The product also performed well when used to treat active infestations. “If you find a wound that is full of maggots and you want to treat it, you can treat it, and within three days we saw 100% therapeutic efficacy against myiasis,” Hutcheson said.
A Valuable New Tool for Producers
As concerns over New World Screwworm continue, Hutcheson believes Exzolt Cattle CA1 provides cattle producers with a powerful new option for both immediate treatment and preventative protection. “It’s a brand new molecule, a new drug class that helps address these challenges that we have,” Hutcheson said.
With both treatment and prevention claims, Exzolt Cattle CA1 could become an important part of the cattle industry’s strategy to prevent the re-establishment of New World Screwworm in the United States.
The Beef Buzz is a regular feature heard on radio stations around the region on the Radio Oklahoma Ag Network and is a regular audio feature found on this website as well. Click on the LISTEN BAR above for today’s show and check out our archives for older Beef Buzz shows covering the gamut of the beef cattle industry today.
