If there is a crest on the horse’s riding tack it would be on a piece of leather extending from his brow band like those on the horses we see at the start of 2×01. This image looks to be of the horse’s neck collar.
I didn’t bother posting the brow part because it’s very plain, looks like just a large round, plain, gem/stud, with a couple of smaller gems/studs in a line above it. Like I said, the bit around its neck was the only ornate decoration that could potentially resemble a crest.
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