Hi!. I know I'm late to the party, but what I use is doggie stairs. My Billy is all body and tiny little legs, so he won't jump off anything. and most of my dogs can't jump on the bed. So, a sturdy set of doggie stairs at the couch and bed will save him from hurting himself. And you only have to watch their blood sugar when they are a young puppy. As they get older, it's not a problem. And I had two tinies, one 2 pounds 11 oz, one 2 pounds 1 oz. and I never had any problems. I free feed, so food is always available. As long as they can eat, they will be fine. It's only the super tinies you really have to worry about. At 5 months, your baby should be fine! I'd love to see a picture!
Pam's Chihuahua Sanctuary