My puppy Howls when he eats?

Okay so My Teacup chiuhuahua was recently sick with parvo and is better now but i dont know if it has anything to do with it or not but he didnt do it before he got sick so i dont know. i was just curious if anyone knows what it means. He just started eating again like 2 days ago and he has only done this twice but he will be right in the middle of eating and look up and howl it is so adorable! It may mean something and it may not so i just thought i would ask. it doesnt bother me at all i just thought it was neat.