Whether or not it’s been a warm or cold winter in your area, winter lice infestations can be a problem. There are two types of lice that infect cattle and both spend their entire lifecycle on cattle hosts:
- Biting lice – feed on the skin and secretions on the outside of the animal
- Sucking lice – these species are blood feeders and pierce the skin
Source: Beef, January 18, 2018.
When treating cattle, it is important to treat the entire group. Missing one animal could allow it to serve as the reservoir for re-infesting the entire herd. The same thought should be given to new additions to the herd from an outside source. Basic biosecurity such as treating and segregating new additions for 30 days is not only good to reduce risk of lice, it is also a great tool in decreasing introduction of other diseases.
INSIGHTS: There are several options when it comes to treatment of lice in cowherds:
- Avermectin endectocides – These products come in pour-on formulations and injectable formulations. Avermectins treat intestinal nematodes and treat external parasites such as lice. (injectable formulations do not work on biting lice)
- Pyrethroid products – very effective against adult lice, but do not affect the larvae or eggs – retreat in 14 days
- Pyrethroid in combination with an IGR (insect growth regulator) – works very well against adults and works against the eggs and larvae – eliminates the 14 day recommended retreatment