My horse has a habit, of eating dirt. He ate it when wer were in hand walking, he just stopped, started sniffing around, and started licking it up. He eats dirt out of the bottom of his water trough, (not the the one we use for water, the ones that's damaged and does'nt hold water.) Small pebbles, Sand like stuff, like the size of pebbles in fish tanks.
Could this be caused by having something missing from his diet? Or it's just someing he does?
Im having the vet out this tuesday, should I ask her about it?