Is a Maltese back supposed to be arched up?

A Maltese dog's back should have a slight arch, which is part of its overall structure, but it should not be excessively arched or sagging. An ideal Maltese has a balanced and well-proportioned body with a level topline when standing. If you notice an abnormal arch or posture, it may indicate a health issue, and a veterinarian should be consulted for evaluation.