When you hear that four-lettered word, what comes to mind?
Humor? Like Lonnie Easterling’s comic line about the young louse that finally faces reality: “Son, your mother and I have decided it’s time for you to move out and infest a head of your own.”
A tongue twister? Try saying “Lousy louse lifecycle, lousy louse lifecycle, lousy louse lifecycle” as quickly as you can.
Or something in the news? “Mutant ‘super lice’ outbreak spreads” … “Super nits resistant to treatment” … “Super lice not budging.”
Yes, there’s a lot of humor out there about lice—and an equal dose of sensational headlines—but when lice are eating at your cattle, horses and pocketbooks, humor quickly takes a backseat.
“While we use the adjective ‘lousy’ to describe something that is worthless, rotten, nasty or second-rate, the term was originally coined to refer to someone infested with lice,” said Doug Ross, senior technical services entomologist for Bayer Animal Health. “So if you want to mix humor with seriousness, I guess you could say that understanding the louse lifecycle and using this knowledge to control them could prevent you from having lousy cattle and a lousy winter.”
Ross, along with Bayer senior technical services veterinarian Larry Hawkins, agreed that knowing the louse lifecycle is critical to get the upper hand on this bothersome critter before it gets the upper hand on your cattle.
“Cattle lice are external parasites that cannot survive more than a few days off their animal hosts,” Ross said. “They have three developmental stages: eggs (also called nits), nymphs and adults.
Ross said that adult female lice usually lay about one egg per day, attaching them to the host animal’s hair. Eggs hatch in about eight to 12 days, depending on the species of louse.
Nymphs hatching from eggs resemble adults but are smaller. The nymphs become fully grown adults in only one to two weeks.
“Adult lice begin laying eggs in as little as three days and can live for two to three weeks,” Ross noted.
Lice typically become a problem during fall and winter, especially in colder states in the middle and northern tiers of the U.S.
“During these seasons when temperatures are cooler, the entire lifecycle—egg to egg-laying adult louse—can take as little as three weeks. Because of that, understanding their lifecycle is critical for effective control,” Ross continued.
Hawkins said that there are two kinds of lice: biting and sucking lice.
The former, also called chewing lice, eat on the skin dandruff of an animal’s hide. “As they move about the animal, they create a lot of itching; therefore, the animals rub and scratch,” he said.
Sucking lice, meanwhile, pierce the skin of cattle and horses, and then suck blood. “This causes irritation that results in the animal scratching itself or rubbing on facilities. When populations are severe, cattle can damage both themselves and your facilities,” he added.
Hawkins has toured both beef cattle and dairy operations following bad outbreaks and said it’s not a pretty sight.
“The cattle are missing large patches of hair, and you see big balls of their hair stuck in fences. Of course, they are uncomfortable so they are twitching their tails and bodies, rubbing and turning around to lick,” he described.
“And when that activity is going on, they aren’t resting or eating, which affects weight gain in stockers, feeders and calves, and it also affects the health of animals.”
For tips on control, please see the other two posts for October, “Don’t let lousy lice cause lousy problems,” and “New technology aids in lice control.”