I don't believe the altitude will bother him. I've never had any problem with mine anyway. Yorkies fly all of the time! Pure pumkin - like Libby's pure pumpkin in a can. It's at wal-mart now since Thanksgiving is coming up. Just be sure it says Pure Pumpkin. It's just handy to have around. A teaspoon or two usually helps. Make him comfortable and warm and he should be happy! My little Muffin had a lot of miles on her. Kacee not so many.
