pokemon never get hurt?

in the game and show the pokemon always return to normal after a trip to the pokecenter. thats probably because they know kids play the game too. if pokemon never got healed like magic, this is what i believe an average marril would look like:
WARNING! may be very shocking compared to a normal marril (jk)



i drew the marril my self :3 its cute but deadly! i also put snow since its getting close to the holidays! (even tho snow has nothing to do with marrils...)