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 2:10-12
10
Sing and rejoice, daughter of Zion; for, behold, I come, and I will dwell in the midst of you,' says Yahweh.
11
Many nations shall join themselves to Yahweh in that day, and shall be my people; and I will dwell in the midst of you, and you shall know that Yahweh of Armies has sent me to you.
12
Yahweh will inherit Judah as his portion in the holy land, and will again choose Jerusalem.