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.

690. In addition it should be realized that one community is never utterly and completely like another, nor one member within a community like any other member. Instead unanimous and harmonious variety of all exists, and these variations have been so ordered by the Lord that they strive towards one single end, which is attained through love and faith in Him. From this arises their unity. For the same reason one heaven and form of heavenly joy is never utterly and completely like another. Indeed variations in love and faith are what determine the nature of heaven and its joy.