Widely debated throughout that animal like creatures are used for fighting is abuse but despite this, in platinum there are a few extra scenes showing animal like Pokemon being used for energy. When interacting with pods they are being kept in, it says that they are suffering and that they look like they are in pain
The move Gastro Acid is described in this way. The animation does not show it coming from the mouth however, it just shows lots of green bubbles/spheres falling on the enemy Pokémon.