Warm weather brings long day, sweat, and a longing for winter time (the last one may just be me), but the heat is not the only thing livestock producers need to consider. External parasites can greatly impact the health of livestock species if no preventative measures are taken. These issues can range from mild aggravation to even death in more serious cases. Generally speaking, producers are more concerned with the loss of gain and milk production caused by these pests.

There are a number of different species of flies that present challenges for livestock. Common species you will find in central North Carolina include horn flies, face flies, and horse flies. Cattle and other species can get stressed out from excessive fly pressure and this can result in poor performance.

Horn flies are small flies that are most commonly found along the sides and back of cattle.

Face flies are a little larger than a house fly and congregate around the nostrils and eyes.

North Carolina has seen reports of the Asian Longhorned Tick, which pose serious health risks to cattle. These ticks carry Theileria, which can cause anemia and death in some cases. First spotted in N.C. in 2010, these non-native pests have moved across the country to Kansas in 2025. Ticks can also carry Anaplasmosis, which infects red blood cells and causes anemia in livestock species.

There are multiple options and practices to manage issues that are caused by flies and ticks. Timing plays a key role in any treatments, but they can all be effective if used correctly. Maintaining pastures so that forage does not get too tall and removing vegetation that are attractive to ticks is a great way to reduce the risk of ticks coming in contact with your animals.

Traps can be used in barns, stalls, or areas where animals congregate to manage local populations of flies. The reuseable outdoor ones work great, but it’s important to check these as they fill up.

Insecticides can also be applied through different methods depending on your management system. Pour/rub-on products, minerals, and tags containing insecticides are all options to treat cattle and they can all be effective if done correctly.

Pour-On & Rub-On

Livestock can treated using a spray/liquid or dry products for external parasites. Dry product is often used in combination with flaps, a fly rub, or back rub, that are placed where animals walk under them. Mineral feeders can also have strips attached to them so animals rub their head and necks on them while getting mineral. Liquid treatments can be sprayed directly on cattle, often along the top line. Other products can be sprayed on the body where flies are observed.

Minerals

Some minerals contain an insect growth regulator (IGR) that passes through the digestive system and makes its way into the manure. Any eggs laid in the manure will not develop and reduces the local fly population. Timing is key when using fly mineral. Feeding needs to start prior to fly season so that the IGR is present in the manure when the flies go to lay their eggs. If feeding is delayed, you will see a delay in effectiveness.

Fly Tags

Fly tags can be effective for both flies and ticks. These tags contain insecticides that are slowly released throughout the effective lifespan of the tag to cover the head and neck. Multiple active ingredients are available and should be used in a rotation.

Resistance

No matter what method is used, it is important to avoid using the same active ingredient year after year. Rotating products with different active ingredients reduces the risk of pests developing resistance to a specific active ingredient. Different ingredients may have varying levels of effectiveness, but using multiple products throughout the years is much better than dealing with an increased level of resistance.