UT Department of Animal Science

With the recent warm weather and rain showers, there has been an increase in tick infestations on Tennessee farms. With this increase of tick infestations and some cattle deaths, this article will give some prevention/treatment options.

🔸Diagnosis
Proper identification of tick species can help pinpoint health issues in a cattle herd. Ticks can be collected from animals and placed in alcohol (not formalin) for preservation, and these samples can be submitted for identification. Tennessee Extension services, Tennessee Department of Agriculture, and the entomology department at the University of Tennessee can all help identify tick species.

🔸Treatment/Prevention
Ticks, including the Asian Long horned tick (ALT) appear to be susceptible to most of the chemical products commonly used to treat other species of ticks on cattle. Some products containing Macrocyclic lactones and organophosphates are both labeled for species of ticks. Pyrethroids have also been recommended to treat cattle that are parasitized with ALT.

Macrocyclic lactones are a class of endectocides that consist of Dectomax®, Eprinex®, Cydectin®, LongRange®, and Ivomec®. Dectomax®, Eprinex®, and Cydectin® pour-ons are all effective in treating animals with ticks. An important note here is that all these products are brand name products. Generic forms of macrocyclic lactones have varied reports of controlling ectoparasites.

Organophosphates come as concentrates that can be mixed up in sprays or applied to backrubbers. Pyrethroid pour-ons like CyLence®, Saber®, Ultra Boss®, and StandGuard® are not labeled for tick control but can be used to treat the ticks. A limitation of the mentioned pour-on treatments is that they may not reach high enough concentrations in the areas that the tick clusters, such as the ears and groin. Many fly tags containing macrocyclic lactones, organophosphates, or pyrethroids are labeled for ticks. It is important to remember that mixing two classes of chemicals together quickly causes resistance. Stick to one class of chemical in all control products for 1-2 years, then swap to a different class. A useful website for selection of control products is https://www.veterinaryentomology.org/. This site allows you to choose the pest to be controlled, species, and application methods. Best of all, it is free to use.

🔸Pasture Control
Treatment of pastures is possible but as I have heard before, it’s about like bear hunting with a switch in the woods at night. Carbaryl (Sevin®) is one example of a product approved to treat pastures for ticks. Before treating pastures, you should consult an expert in your area and only treat those areas with the densest tick populations.

Other helpful recommendations for controlling ticks are to fence cattle away from swampy areas and woods and keep pastures clipped short. The ALT especially prefers shaded moist areas such as tree lines and creek banks. Unfortunately, these recommendations can negatively impact beef cattle production and may outweigh the benefits of tick control. Furthermore, wildlife can drop ticks off as they pass through pastures, reintroducing ticks into previously treated and/or fenced areas. Successful treatment and control programs for ALT will require an integrated approach. A single application of any of these products is unlikely to provide complete control of most tick species.

Tick control requires diligence but not overuse of products. Consult with your Extension agent, or local veterinarian, before starting any control protocol to ensure it is the best suited for your situation, and always follow labelled directions when applying chemicals. Always wear PPE equipment when applying. Please feel free to contact me. 865-974 3538, [email protected], or askdrlew.tennessee.edu

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Dr. Yanqiu Yang joins us to talk with Dr. Bruno Pedreira and Dr. Katie Mason about precision beef technologies!

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The Tennessee Department of Agriculture has issued temporary animal import requirements following a recent detection of New World screwworm in Texas.

There is currently no indication of an outbreak in Tennessee. This proactive order focuses on education, early detection and prevention to help protect animal health.

New World screwworm is a parasitic fly that can affect warm-blooded animals, especially through open wounds. Animal owners, producers, veterinarians and transporters are encouraged to monitor animals closely, especially wounds and areas around the nose, ears, eyes, mouth and genitalia.

Watch for drainage, discharge, bleeding, swelling, discomfort, lethargy, isolation or unusual odors.

Suspected cases must be reported to the Tennessee State Veterinarian’s Office within 24 hours at 615-837-5120 or [email protected].

To read more about the order, visit:
tn.gov/agriculture/animals/animal-health-resources/alerts.html

The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has provided an important update on New World Screwworm which has been detected in a bovine in Zavala County, Texas. Read the full press release here: https://www.aphis.usda.gov/news/agency-announcements/usda-confirms-presence-new-world-screwworm-united-states

General information about New World Screwworm (NWS) can be found in the text below and in the attached infographic.

The adult screwworm fly is about the size of a common housefly (or slightly larger), with orange eyes, a metallic blue or green body, and three dark stripes along its back. It gets its name from the behavior of its larvae (maggots) as they burrow (screw) into the wound, feeding as they go. The maggots (larvae) cause extensive damage by tearing at the hosts’ tissue with sharp mouth hooks. The wound can quickly become enlarged and deeper as more maggots hatch and feed on living tissue.

Because they feed on live flesh, NWS maggots may burrow deep into wounds or openings, while other species of maggots may appear around the outer surface of the wound. In addition, even the smallest wounds have the potential to attract flies, so it is imperative that you keep a close eye on your animals for any signs of wounds.

Lastly, NWS infestations are a reportable disease! Immediately report any suspicious wounds, maggots, or infestations to a local accredited veterinarian, your State Animal Health Official, or a USDA veterinarian.

For more information, reference this resource from the U.S. Department of Agriculture: https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/stop-screwworm

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Thank you to everyone who attended the 2026 Animal Science Scholarship and Awards Banquet! We are especially grateful to our generous donors for their continued support of our students and for helping provide opportunities for them to learn, grow, and succeed.

Congratulations to Kallie Noblin on receiving the Excellence in Advising Award at the Academic Honors Banquet!
This recognition is incredibly well deserved and reflects Kallie’s dedication, guidance, and lasting impact on students every day.

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