Known for his gentle, loving personality and stocky, muscular build, the American bulldog is a taller, leaner version of his wrinkled counterpart, the English bulldog. Growing to 60 to 120 pounds, these generally healthy dogs live from 10 to 16 years.
As a larger breed dog, the American bulldog reaches his full height between 12 and 18 months of age. His body may continue to bulk up until he reaches between 2 and 3 years of age. The length of time it takes your American bulldog to reach his adult size depends to some degree on how large he will be when he is full grown. Typically, the larger the adult dog, the longer he grows.
On his journey to becoming an adult, your American bulldog puppy will pass through many mental and emotional stages of maturity. Events he encounters between 7 and 12 weeks of age will remain with him for a lifetime, making this stage of development particularly important. Depending on your dog's individual personality, he will reach mental adulthood between 1 and 4 years of age.