If cattle seem to be scratching excessively against trees, posts, and feeders, to the pint of rubbing off large patches of hair or creating raw sores, lice may be the reason. The species of biting and sucking lice that infest cattle are most numerous and active during the winter and can spread easily through the herd as cattle bunch in response to cold temperatures. Confirm that lice are the reason for the scratching by examining some animals in the herd. Part the animal's hair in spots where lice are likely to occur and look for lice eggs (nits) attached to hairs.

The single species of the biting louse on cattle is about 1/12 inch long with a yellow-white body and wide red head. It can be found all over the bodies of young and mature cattle. This oouse feeds on skin, skin secretions, and hair and is irritating. There are three species of sucking lice; they are blood feeders. These lice are most commonly found on the head, neck, brisket, withers, around the base of the tail and along the inner surfaces of the legs. Shortnosed and little blue cattle lice are more often found on older animals, the little blue louse tends to occur on the head. The long-nosed cattle louse is most often found on young cattle.

If lice are present, two insecticide applications may be needed to clean-up the infestation. The first treatment kills active adult and immature lice but does not kill nits or eggs on the hide. The second application, about 14 days later, targets newly hatched lice.

There are plenty of lice to go around. Different species also attack horses, goats, and swine, the signs and impact on these animals are very similar to what is seen on cattle, the control approach is similar, also.