Systemic, non-systemic lice control products available for treating cattle
According to University of Nebraska-Lincoln Extension Educator David Boxler, lice control in cattle is important both for animal performance and profitability.
With many products available to choose from, Boxler outlined the differences and important factors to consider when choosing a product.
“There are two types of control products available, non-systemic, which work by contact, and systemic products, which work by being absorbed internally into the animal,” said Boxler.
Some non-systemic pour-on formulas provide control with only one application, said Boxler.
“Some of those formulations include Boss, Saber, StandGuard, Ultra Boss and Ultra Saber,” he explained.
Alternatively, other non-systemic pour-on formulations require two applications, typically spaced 14 days apart.
“Some of those products include Cattle Armon, CyLence, Permectrin, PROZAP, Synergized DeLice and Y-TEX BRUTE,” commented Boxler.
Because of the different application requirements, Boxler stressed, “Be sure to read the label when selecting a non-systemic product.”
Boxler noted that there is also a non-systemic product that contains an insect growth regulator called diflubenzuron and also a synthetic pyrethroid insecticide.
He explained, “An insect growth regulator works by disrupting the growth stages of the cattle louse.”
According to Boxler, systemic endectocide pour-ons are effective against both chewing and biting lice.
He noted that there are differences between the chemicals in handling and efficacy.
“Some endectocides have slaughter withdrawal restrictions, and some are rain-fast, while others are not,” commented Boxler.
As such, he encouraged producers to check the label of the products they plan to use.
In addition to pour-ons, Boxler explained that there are also injectable formulations that are available.
“There are endectocide injection formulations available, but these work better on sucking lice than on chewing lice,” said Boxler.
The type of endectocide used is important to consider when choosing when to treat animals, said Boxler.
In particular, he cautioned producers to not to use a systemic endectocide between Nov. 1 and Feb. 1.
“It is not advised, as they may cause a host parasite reaction in the animal by killing cattle grubs that may be developing in the esophagus and spinal canal of the animal,” explained Boxler.
He noted that if a systemic endectocide was applied during fall weaning, producers should not have a problem with host parasite reactions, as that is typically before the critical time window.
Boxler continued, “Producers who did not use a systemic endectocide during fall weaning should consider only a non-systemic control product during the Nov. 1 to Feb. 1 timeframe.”
According to Boxler, proper application timing is critical to successful control programs.
He noted that many producers apply endectocides during fall weaning, as it’s a convenient time.
“Many producers will administer an endectocide treatment at fall weaning with intentions of controlling internal parasites, cattle grubs and cattle lice,” said Boxler.
While these fall applications may reduce numbers, Boxler stressed, “Fall application may not totally remove the infestation.”
When there is a warm fall, the weather may slow down the developing lice numbers, which may not be indicative of the rest of the fall and winter.
“Livestock producers who use this management strategy should monitor their cattle for signs of lice, especially during the months of December, January and February,” continued Boxler.
Producers should take special care to treat replacement animals that come into the herd during the winter months.
“If replacement animals are brought into the herd during winter months, they should be examined for lice,” he concluded. “If lice are present, the animals should be isolated and treated before introduction to the existing herd.”
Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at firstname.lastname@example.org.