These canines are relatively small, as they don’t go beyond 18 pounds. This is usually the case with all Cavalier puppies. However, there are Toy Cavalier puppies that qualify among the smallest dog breeds in the world. They make a separate case. The Cavalier King Charles Spaniel growth chartrequires long hours of organizing, planning, and preparing. However, once you succeed, the rest is a piece of cake! Their weight might go up or down by a few pounds, but excessive weight gain, or weight loss is a sign of a serious condition. Overweight puppies are considered to be obese. Obesity harms their overall well-being and makes them susceptible to diabetes, or bone injuries. On the other hand, excessive weight loss is a sign of a serious health condition in a Cavalier dog.