Was Glorfindel's horse one of the Mearas?

[Inziladun]

Originally Posted by Galin

It's interesting (or maybe not) that more than 1,000 years before we meet Asfaloth, Glorfindel rode up on his "white" horse to meet the Witch-king. And my impression anyway, was that this horse would stand before the Wraith, although possibly due to Glorfindel...

Glorfindel's influence is my stance. See how Legolas, even though not as exalted in spiritual status as Glorfindel, was able to get the normal horse Arod to enter the Paths of the Dead.

Also, the mearas are represented as only being tied to the Rohirrim (Éothéod).

It was upon Felaróf that Eorl rode to the field of Celebrant; for that horse proved as long lived as Men, and so were his descendants. These were the mearas, who would bear no one but the King of the Mark or his sons, until the time of Shadowfax.

ROTK Appendix A