Sheep lice facts
The sheep body louse (Bovicola ovis) is responsible for most infestations of Australian sheep.
It is a pale yellow insect less than 2mm long.
- broad red to brown head
- red to brown stripes across the body.
How infestations happen
Most new infestations start from contact with other infected sheep either:
- purchased sheep, including rams
- stray sheep from other mobs or other properties.
Other lice infestations come from a failure to eradicate sheep lice at a previous treatment.
Keep purchased sheep isolated for as long as possible. Check all purchased sheep thoroughly while they are isolated. Check your sheep health statement for information on previous treatments used.
Good fences are the most effective method of preventing lice. It is very unlikely that lice will cross a fence line, unless they are attached to a stray sheep.
Lice build up and transfer
Lice spread slowly in the early stages of an infestation. It can be very difficult to find lice in the first 3 months of an infestation. Once signs of lice are seen the infestation can spread rapidly.
Lice transfer between sheep when sheep rub against each other, this occurs:
- during yarding and shedding
- in sheep camps or at the water trough
- any time sheep are in close contact.
Lice transfer quickly when sheep have short wool or sheep are heavily infested.