Pokemon arnt the animals in the pokemon world you just dont see a lot of the normal animals.
Source
But they sometimes reffer to eating pokemon.
>It is stated in multiple Pokédex entries that some Pokémon are known to eat others, such as Pidgeot swooping down to catch a Magikarp meal from the water. Humans have also been implied to eat Pokémon, with the player's mother's Cinnabar Volcano Burgers and Team Rocket's plot to sell Slowpoketails as a sweet treat in Generation II and Pokémon HeartGold and SoulSilver. Farfetch'd itself is based on a specific manner for preparing a meal of duck, with its rarity in the wild being a result of overhunting. Several of the Sinnoh myths also mention eating Pokémon, saying that they will be born again if their bones are picked clean and returned to where the Pokémon was found.-Source
and just for kicks here is a video of actual animals in the pokemon episodes. Here is another.