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.

241. Verse 18. I counsel thee, signifies the means of reformation of those who are in the doctrine of faith alone. This is evident from what now follows, for the reformation of those who are in that doctrine is now treated of; therefore "I counsel thee" implies precepts as to how such must live that they may be reformed and thus saved.