Rick Riordan said this quote

As I got closer to the fence, I held my shirt over my nose to block the smell. One stallion waded through the muck and whinnied angrily at me. He bared his teeth, which were pointed like a bear's.I tried to talk to him in my mind. I can do that with most horses.I'm going to clean your stables. Won't that be great?Come inside! Eat you! Tasty half-blood!Usually this gets me VIP treatment in the equestrian world, not this time.Poseidon can come in, too! We will eat you both! Seafood! The other horses chimed in as they waded through the field.