Instructions
Call your pet by using the Call Pet spell. Once your pet appears, right-click his unit frame at the top. left of the screen. Click "Pet Details."
Move your mouse over the small bone icon at the top, right of the "Pet Details" window. Your pet's diet will appear. The food you can feed your pet depends on the type of pet you have. For example, if you hover over the bone icon for a crocodile, you will see "Diet: Meat, Fish." That means you can only feed your pet meat or fish.
Click your Feed Pet spell, which is located in either your Spellbook on your Actionbars. A silver glove will replace your cursor after you click the spell. Open your inventory and click the type of food your pet will eat. The food will replenish 50 percent of your pet's health.