Pet food can be purchased from the Stable Keeper, the Central Marketplace, or the Pearl Shop.
Buying Pet Food From the Central Marketplace: This is the preferred method of buying pet food. Search for feed in the central marketplace and purchase either cheap feed, good feed, organic feed, or balanced feed.
Buying Pet Food From Stable Keeper: To locate the nearest stable keeper, press the horse icon right next to the map. This will point you towards the closest stable keeper. Once you talk to the stable keeper, press 1 or “NPC Shop”. Cheap Feed is pet food.
Buying Pet Food From Pearl Shop: Search for feed in the pearl shop. This is not recommended since it can be bought with silver.