Most farmers have cattle housed eight weeks or longer at this stage, and have given all their livestock some form of a parasite-control programme.

While livestock may have been treated for lice at housing, many farmers have reported noticing them showing symptoms of lice again.

If livestock are showing symptoms of lice, a secondary lice treatment may well be necessary.

The symptoms of lice on cattle are as follows:

  • Scratching;
  • Licking;
  • Tail swinging;
  • Hair loss;
  • Inflamed skin.

There are many reasons why a secondary outbreak of lice can occur – including if new livestock were introduced to the shed after the herd were treated – but another factor is that the initial treatment may not have controlled all lice.

The two main types of lice that affect cattle are biting lice and sucking lice.

Injectable products for treating lice will primarily treat sucking lice, and will aid in the control of biting lice, however pour-on treatments will treat both sucking and biting lice. Before selecting the treatment to use, farmers should consult with their veterinary practitioner.

Approximately three weeks after the initial lice treatment, farmers should check to make sure their cattle are showing no signs of lice.

The reason livestock may have to be treated again after three weeks is to kill-off any lice that may have hatched from eggs since cattle were last treated.

Before using a lice treatment on forward-type beef cattle, farmers should check the withdrawal period on the product.

Lice are an external parasite and an outbreak in a shed of cattle can be easily controlled, but can have a major impact on livestock performance if left ignored.

When treating cattle for lice, it is important to treat all the livestock that are in close contact at the same time to get the best control of the parasite.