Horse
In Ezekiel 26:11, this signifies the love of learning or intellectual things. (Arcana Coelestia 3727)
In Revelation 6:2, this signifies the love of understanding the Word. (Apocalypse Revealed 298)
In Zechariah 12:4, this signifies that the intellectual should be filled with falsities. (Arcana Coelestia 2383[2])
In general, 'a horse' signifies knowledge or understanding of the Word. In an opposite sense it signifies the understanding of the Word falsified by reasonings, and likewise destroyed from self-derived intelligence. 'A dead horse' signifies no understanding of truth from the Word.
Zechariah 8:9
9
Thus says Yahweh of Armies: "Let your hands be strong, you who hear in these days these words from the mouth of the prophets who were in the day that the foundation of the house of Yahweh of Armies was laid, even the temple, that it might be built.
