Passage 9.13.4
ἐνταῦθα καὶ αὐτῷ Κλεομβρότῳ καὶ Λακεδαιμονίων τῷ κοινῷ σημεῖα ἐγένετο ἐκ τοῦ θεοῦ. τοῖς βασιλεῦσιν αὐτῶν ἐς τὰς ἐξόδους πρόβατα εἵπετο θεοῖς τε εἶναι θυσίας καὶ πρὸ τῶν ἀγώνων καλλιερεῖν· ταῖς δὲ ποίμναις ἡγεμόνες τῆς πορείας ἦσαν αἶγες, κατοιάδας οἱ ποιμένες ὀνομάζουσιν αὐτάς. τότε οὖν ὁρμήσαντες ἐς τὴν ποίμνην λύκοι τοῖς μὲν προβάτοις ἐγίνοντο οὐδὲν βλάβος, οἱ δὲ τὰς αἶγας τὰς κατοιάδας ἔκτεινον.
At this place, signs from the god appeared both to Cleombrotus himself and to the Spartan people in common. It was customary for their kings, whenever they set out on expeditions, to have sheep accompany them for sacrifices to the gods and divination before battles; yet in these flocks goats served as leaders on the march, which the shepherds call "katoiades." At that time, wolves attacked the flock, but no harm befell the sheep; instead, the wolves killed only the goats called "katoiades."