During a recent webinar, a group of large-animal veterinarians discussed the habitual characteristics of lice and ways to help beef and dairy cattle producers manage these troublesome insects.
They agreed that knowing the signs and symptoms are among the key initial steps to avoiding a costly outbreak in their herds.
“If you look across a pen or a pasture holding 200 cattle and see one animal rubbing a fence, one switching a tail, one swinging its rear end around, one licking on its withers and one dancing, take those collective actions very seriously,” said Dr. Larry Hawkins, senior technical services veterinarian with Bayer Animal Health.
“You want to see your animals comfortably standing, lying down or ruminating after they’ve been fed,” Hawkins said. “We call that cow comfort.”
But if a few of your beef or dairy cattle have become fidgety for no apparent reason, pests such as mites or lice might be the culprits.
“Don’t wait for a severe outbreak before you take any action,” Hawkins urged. “This begins with a close physical examination. When it comes to problems like lice, I’ll never forget the words of one of my professors in veterinary school: ‘You will miss more things for not looking than you will for not knowing.’”
Hawkins emphasized: “The point that he was making was a good physical exam does a lot. Getting cattle in the chute and giving them a careful look to see if they have lice, or if something else is causing the problem – or perhaps your previous treatment(s) successfully treated the lice and your cattle need to get over the ‘itch reflex.’”
Use both hands to part hair on the face, top line and withers. If you find up to five lice per square inch, a problem is brewing. If there are six to 10 per square inch, it’s time to begin a treatment program.
More than 10 are considered a heavy population, which points to a breakdown in that key preventive step called “vigilance.”
“In a herd infested with lice, there is constant activity. Your cattle will be rubbing on something, switching their tails and swinging their back ends,” Hawkins said. “They move their feet up and down trying to get relief from an irritation. They’ll dance around.”
Since lice are cold-season insects, this type of activity could begin building in the fall months.
“Get help from your veterinarian in identifying lice, mites and other pests that cause itching. Establish a firm diagnosis and then work together to develop a treatment program,” Hawkins suggested.
This will help avoid those wrecks that he and other veterinarians get called to each winter, when dozens of cattle in one herd have literally rubbed large patches of hair off their shoulders because of the intense irritation.
“It’s really sad to see animals with bare pink skin on both shoulders in December and January. You can tell those animals don’t feel well, that they’re not healthy,” Hawkins said. “But you can avoid situations like this if you monitor. If you start seeing any signs of lice or other pests, get a few cattle in the chute and see what’s going on.”
In an upcoming story, Dr. Hawkins will offer management strategies to effectively control lice.