SWAT Pour-On for cattle will give effective control of pyrethroid susceptible Buffalo fly and Cattle Lice when used as directed. The level and duration of control may be reduced due to high fly pressure. Treat all animals in the group. The length of residual protection against Buffalo flies will vary depending on the level of insecticide resistance within a particular area. SWAT Pour-On is effective against biting lice and two species of sucking lice.