Tips for Combatting Winter Lice in Beef Cattle

Keep lice at bay in your cattle herd with these tips for implementing a strategic lice control program

At a glance 

For beef producers, lice present an ongoing problem for cattle, especially in winter and particularly in colder climates. Lice can rob cattle of valuable performance when it’s needed most and decrease weight gain. 

While you may have treated for lice in the fall, there is a good chance you could see them begin to reemerge depending upon the product you used and when you timed your application. It’s important for cattle producers to understand there are two types of lice of concern: blood sucking and chewing. When it comes to blood sucking lice, systemic treatments work to kill these pests and, while topical treatments will kill both blood sucking and chewing lice, in either case, only the adults are killed, leaving the eggs to hatch and reinfest the herd.  

Traditionally, to break this cycle and give season-long control, producers have to treat all the animals in the herd 2-3 weeks following the first application, just after the eggs have hatched but before they get a chance to lay new eggs. However, by using a single application product that kills lice at multiple life stages including the eggs, producers can eliminate lice infestations while saving time and money and sparing their cattle the stress of being put through the chute a second time. 

When choosing a single-dose product, it’s important to properly apply it at the right time of year to provide season-long control for your entire herd. 

The right time of year

Lice do not thrive in warm weather, so when the temperature gets too high on cattle, it will kill them. This is why we don’t see lice in the summertime. The few that survive make their way down to the cooler areas on the flank, armpits and ears. In most cases, all but just a few animals in the herd will be lice-free during summer. It isn’t until well into fall and early winter that the lice start to reproduce and reinfest their host and ultimately the rest of the herd.  

It doesn’t matter what you pour on the cattle’s back, if the lice aren’t out, it can’t kill them. When you turn to your neighbor and say, “Yep, winter’s here,” the lice are probably saying the same thing, and this should signal you to treat. 

Proper application

To kill the lice and eggs, the active ingredients need to come in direct contact with them. It’s important to apply product directly to the hide from between the ears, down the midline and all the way to the tailhead.  

This is easier said than done and it is not recommended to give this task to an untrained employee. In the end, misapplication can end up costing you a lot of dollars for the entire herd, not just the one or two animals missed or mis-treated. If all animals are not properly treated, once the chemical is gone the whole herd could get reinfested, just like when coming out of summer. 

Here are some pointers for proper treatment: 

Keep lice at bay year-round

While broad-spectrum, pour-on dewormers (endectocides) should only be used when internal parasites are the primary target, they can provide added benefits for lice and fly control. Treating with an endectocide at spring turnout can help in killing off any remaining lice from the winter months. This can also facilitate fly control, if they are present, with an added knockdown to enhance fly tag performance. When we head into fall, deworming with endectocides can help keep lice at bay until winter treatment. 

To learn more about a strategic lice control protocol, talk with your veterinarian or Elanco technical representative.