Neapolitan Mastiff (Dog): Size, Temperament & Puppies

The Neapolitan mastiff is a formidable breed. He is watchful, loyal, and protective of his family, but tends to be wary of people he doesn't know. The dog will thrive with the right person who is willing to put in the time to give him the training he needs, but this giant is not a good fit for people or families who don't understand how to work with the Neapolitan mastiff temperament. Proper training and socialization are critical.

The Neapolitan mastiff dog — you might see this name written as neo mastiff or Mastino — has a massive head covered in wrinkles and long, drooping lips. His strong, heavy body is covered in loose skin and wrinkles. He has a short, dense coat with straight fur that is black, blue, gray, mahogany, or tawny.

Male Neapolitan mastiffs grow to be 26 to 31 inches tall and 150 pounds while females are 24 to 29 inches tall and 110 pounds. The dog has a fairly short life expectancy and only lives an average of 7 to 9 years. The breed is a part of the American Kennel Club's working group.

Breed is not a reliable indicator of personality, however, Neapolitan mastiffs tend to be loyal, protective, and trusting of their human companions. They are quiet and even-tempered but may be aggressive to other people and animals. Separation anxiety is a concern for some dogs.

Due to their large size and protective instincts, it is critical that these dogs are socialized with people and dogs when they are young. As puppies mature into teenagers, they become rambunctious and stubborn. Start Neapolitan mastiff training when the dogs are young. Use plenty of positive reinforcement and consider hiring a qualified dog trainer to help you.

The Neapolitan mastiff has a short coat and minimal grooming needs. Brush him weekly and give him the occasional bath. Keep his nails trimmed and be sure to check his ears regularly for infection. This breed tends to drool, so keep a towel handy to wipe his face and mouth as needed. Gently wipe his eyes as needed.

Puppies and adolescent dogs are very playful while adults tend to be more relaxed. Even as adult dogs begin to settle, be sure to give them regular exercise each day. Puppies can easily injure their joints when jumping or making abrupt turns, so take care when playing with your pup and avoid stairs when possible. Watch your dog carefully, especially during the summer months, to make sure he doesn't overheat. Avoid roughhousing and tug of war as forms of play and exercise.

Neapolitan mastiffs don't have many health problems. Cherry eye is a concern. This occurs when the gland in the corner of the eye becomes swollen and red. Surgery is sometimes necessary, but your vet will likely prescribe an eye ointment to try first. Bloat is also a concern in this large breed. Recommended health testing for Neapolitan mastiffs includes a hip and elbow evaluation, ophthalmologist exam, and cardiac exam.

A Neapolitan mastiff puppy grows quickly during the first year of life. They continue to grow and fill out until they reach 19 to 22 months of age. A male Neapolitan puppy will weigh an average of 43.7 to 48.5 pounds when they are three months old and grow to weigh 78.6 to 88.2 pounds when they are six months old. At a year, they grow to 120.1 and 136.7 pounds.

Female puppies weigh 37.6 and 43.7 pounds at three months of age and 69.5 to 78.6 pounds at six months of age. They typically weigh between 102 and 120.1 pounds when they reach one year of age.