Canus patrol is a group of four Cylon Raiders attached to Specter's Attila garrison command.
This patrol encounters two Vipers from Galactica and engages the patrol, resulting in the destruction of three Raiders, with a fourth escaping after inflicting severe damage to Starbuck's Viper.
Specter recalls the surviving Raider, which contains the flight leader, after detecting that the Viper penetrated the atmosphere (TOS: "The Young Lords").