I found the phrase “... the horse which ran was not the horse nor of the age which he was represented to be at the time of entry ...” in a sentence of Codes, Rules and Regulations of the State of New York 9 Executive (E) - Chapter 1, Subchapter A : State Racing Board Thoroughbred Rules, 4039.19. [→]
Is which wrong in the phrase above, or is it the exact word as the horse is a brute animal?
To be clear, which is grammatical : "... the horse which ran ..." or "... the horse who¹ ran ..."?
¹ See the following nGram for "cat who" (cat: no brute), "dog who" (dog: no brute), "horse who" (horse: brute) and "bull who" (bull: brute).