Signs Your Puppy Is Overweight
Only a veterinarian can accurately and thoroughly assess whether or not a dog is overweight or obese. But you can look for the following signs that might indicate an excess of dog fat. A healthy dog's waist, not belly, shows when viewed from above, and a belly that appears tucked in when viewed from the side. The sides of the puppy might not be as tucked in as the sides of a dog but there shouldn't be be visible fat coming out from the sides of his body. The ribs should not be easily felt under a thin layer of flesh and not visible to the naked eye. An obese puppy may have fleshy deposits over the base of the tail, the chest or the spine. Obesity is a sign of a serious health issue and should be addressed with your vet immediately.
Breed Size and Puppy Weight
Learn about the breed of your puppy if at all possible. If the puppy is purebred or both the parents are known, obtain the weight of the father and the mother. You now have a goal estimate for the puppy once full grown, i.e. the male puppy should get to his father's weight and the female should get to her mother's weight.
Even if you don't know the sire and dam, determine what type of breed the puppy is. If the puppy is a toy or small breed, he shouldn't exceed 20 pounds when grown. A medium breed should stay under 80 pounds, and a large breed like a Great Dane can get up to 200 pounds. Most labs and regular large breeds stay under 150 pounds.
You can also take the weight of your puppy at 6 weeks and double it twice. This is probably what he will weigh as an adult. So a small puppy that weighs 5 pounds at 6 weeks, will weigh 20 pounds as an adult because 5 times 2 is 10 and 10 times 2 is 20. A medium puppy's weight at 14 weeks can be doubled once to determine their adult weight and a large breed puppy's weight at 6 months yields the same result.