Our Resources On The First 24 Months, Temperament, Neurological Stimulation, and Early Socialization
Mastiff Puppy Development Series
The Adolescent Stage in English Mastiffs: What Happens Between 6–18 Months
The adolescent stage in English Mastiffs typically occurs between 6 and 18 months of age and is often the most challenging period for owners. During this time, puppies may temporarily regress in training, test boundaries, become more independent, and show fluctuating energy levels.
Is My English Mastiff Growing Normally?
English Mastiffs grow more slowly than many other breeds and continue developing until approximately 18 to 24 months of age. While owners often compare their puppy's weight or height to other dogs, healthy development depends on much more than size alone.