sool

verb

1. To encourage (especially a dog) to attack.

   “My neighbour sooled her bull mastiff onto my chihuahua, because she was sick of its yapping and wanted it to meet its demise.”

   “She went quickly towards her camp, calling softly, "Birree gougou," which meant "Sool 'em, sool 'em," and was the signal for the dogs to come out.”