Infestation levels are measured by counting the number of lice per square inch on the skin of cattle. These locations include the face, dewlap, neck, back and the base of the tail. There are some clues that can indicate a louse problem. A change in animal behavior, such as frequent rubbing and scratching by cattle on equipment and fencing, is generally a good indicator. Scruffy and unkempt hair coats often accompany moderate to heavy infestations of lice.
Animal nutrition appears to be related to louse problems.
Animals stressed by extreme cold or shipping may also show buildups in louse populations. A variety of application techniques and chemicals are currently registered for control of lice on cattle. Application methods include sprays, dips, dust bags, oilers, pour-ons and injections. Currently approved and recommended materials and their methods of application for louse control on North Dakota cattle are listed in the North Dakota Insect Control Guide and in the Extension Circulars Insect Pests of Cattle, No. E-433 and Approved Dairy Cattle Sprays, No. E.330. These publications are available through your county Cooperative Extension Service office.