In Anna Karenina, who does Vronsky's horse represent? [spoilers for the book]

In Part II of the novel, Vronsky breaks the back of his beloved prize mare Frou-Frou. We know what he covets the other horse, Gladiator, who goes on to win the steeplechase. There is nearly universal agreement that the horse is a metaphor for a woman in Vronsky’s life.

I hold that Frou-Frou is Kitty, and Gladiator is Anna. After all, Anna wins the race in his heart, which devastates Kitty, “breaking” her and sending her to an invalid’s retreat for several weeks. However, I’m told that many Tolstoy scholars have decided that Frou-Frou represents Anna somehow.

I’m reading along with my SO and my sister, who are in book club together. My SO and I think it’s Kitty, and my sister (who studied this book back in college) says it’s Anna.

What say you?

I never thought it was anyone but Anna, as a foreshadowing of how her relationship with Vronsky turns out.

Oops, never mind.

The horse is female, but I still always saw it as a representation of himself, or at least his own life. He was toxic to everything he touched.

I think it works either way, but the more obvious interpretation is Kitty, I think. His infatuation with Anna/Gladiator causes him to be careless towards Kitty, leading to her injury.

The obvious counter-argument is that Kitty doesn’t end up dead…