Size, Proportion, Substance: 
A stocky, heavy boned dog, massive in substance, rectangular in proportion. Length  
of body is 10% - 15% greater than the height at the withers. Height: Dogs: 26 to 31  
inches, Bitches: 24 to 29 inches.  

Average weight of mature :  
Dogs = 150 pounds; Bitches = 110 pounds;  
but greater weight is usual and preferable as long as correct proportions and function are maintained.  
Disqualification's:  
Absence of massiveness  

Head:  
Large in comparison to the body. Differentiated from that of other mastiff breeds by more extensive wrinkling and pendulous lips which blend into an ample dewlap. Toplines of cranium and the muzzle must be parallel. The face is made up of heavy wrinkles and folds. Required folds are those extending from the outside margin of the eyelids to the dewlap, and from under the lower lids to the outer edges of the lips.  
Severe faults:  
Toplines of the cranium and muzzle not parallel.  
Disqualifications: 
Absence of wrinkles and folds  

Expression:  
Wistful at rest, Intimidating when alert. Penetrating stare.  

Eyes:  
Set deep and almost hidden beneath drooping upper lids. Lower lids droop to reveal the haw.  
Color:  
Shades of amber or brown, in accordance with coat color. Pigmentation of the eye rims same as the coat color.  
Severe faults: 
Whitish blue eyes; depigmentation of the eye rims.  

Ears: 
Set well above the cheekbones. May be cropped or uncropped but are usually cropped to an equilateral triangle for health reasons. If uncropped, they are medium sized, triangular in shape, held tight to the cheeks, and not extending beyond the lower margin of the throat.  

Skull:  
Wide, flat between the ears, slightly arched at the frontal part, and covered with wrinkled skin. The width of the cranium between the cheekbones is approximately equal to its length from occiput to stop. The brow is very developed. Frontal furrow is marked. Occiput is barely apparent.  

Stop: 
Very defined, forming a right angle at the junction of muzzle and frontal bones, and then sloping back at a greater angle where the frontal bones meet the frontal furrow of the forehead.  

Nose: 
Large with well opened nostrils, and in color the same as the coat. The nose is an extension of the top line of the muzzle and should not protrude beyond nor recede behind the front plane of the muzzle.  
Severe faults:  
Depigmentation of the nose  

Muzzle:  
It is 1/3 the length of the whole head and is as broad as it is long. Viewed from the front, the muzzle is very deep with the outside borders parallel giving it a "squared" appearance. The top plane of the muzzle from stop to tip of nose is straight, but is ridged due to heavy folds of skin covering it.  
Severe faults: 
Top plane of the muzzle curved upward or downward.  

Lips:  
Heavy, thick, and long, the upper lips join beneath the nostrils to form an inverted "V" The upper lips form the lower, outer borders of the muzzle, and the lowest part of these borders is made by the corners of the lips. The corners turn outward to reveal the flews, and are in line with the outside corners of the eyes. 

Bite:  
Scissors bite or pincer bite is standard; slight undershot is allowed. Dentition is  
complete.  
Faults:  
More than 1 missing premolar. Severe faults: Overshot jaw: pronounced undershot jaw which disrupts the outline of the front plane of the muzzle; more than 2 missing teeth.  

Neck, Topline and Body - Neck:  
Slightly arched, rather short, stocky, and well muscled. The voluminous and well divided dewlap extends from the lower jaw to the lower neck.  
Disqualification:  
Absence of dewlap.  

Body: 
The length is 10% - 15% greater than the height of the dog at the withers. Depth of the ribcage is equal to about half the total height of the dog. Ribs are long and well sprung. Chest: Broad and deep, well muscled. Breast bone is level with the point of the shoulder. Underline and tuckup: The underline of the abdomen is practically horizontal. There is little or no tuckup. Back: Wide. Withers are wide and long, barely rising above the strong topline of the back. Loin: well muscled and harmoniously joined to the back. 

Croup: 
Wide, strong, muscular and slightly sloped. The top of the croup rises slightly and is level with the withers.  

Tail:  
Set on slightly lower than the toppling, wide and thick at the root, tapering gradually toward the tip. It is docked by about 1/3. At rest, the tail hangs straight or in slight "S" shape. When in action, it is raised to the horizontal or a little higher  
than the back.  
Severe fault:  
Tail carried straight up or curved over the back. Kinked tail.  
Disqualification: 
Lack of tail or short tail, which is less than 1/3 the length from point of insertion of the tail to the hock.  

Forequarters: 
Heavily built, muscular, and in balance with the hindquarters.  

Shoulders:  
Long, well muscled, sloping and powerful.  

Upper arms:  
Strongly muscled, powerful. In length, almost 1/3 the height of the dog.  

Elbows:  
Covered with abundant and loose skin; held parallel to the ribcage, neither  
tied in nor loose.  

Forelegs:  
Thick, heavy boned, well muscled, exemplifying strength. About the  
same length as the upper arms. And set well apart.  

Pasterns:  
Thick and flattened from front to back, sloping forward from the leg.  
Front Dew claws: Front dew claws are not removed.  

Feet:  
Round and noticeably large with arched, strong toes. Nails strong, curved and  
preferably dark colored. Slight turn out of the front feet is characteristic.  

Hindquarters: 
As a whole, they must be powerful and strong, in harmony with the forequarters.  

Thighs: 
About the same length as the forearms, broad, muscular.  

Stifles: 
Moderate angle, strong. Legs: Heavy and thick boned, well muscled. Slightly shorter than the thigh bones.  

Hocks: 
Powerful and long.  

Rear pasterns (metatarsus):  
Heavy, thick bones. Viewed from the side, they are perpendicular to the ground. Viewed from the rear, parallel to each other.  

Rear dew claws: 
Any dew claws must be removed.  

Hind feet:  
Same as the front feet but slightly smaller.  

Coat: 
The coat is short, dense and of uniform length and smoothness all over the body. The hairs are straight and not longer than 1 inch. No fringe anywhere. 

Color: 
Solid coats of grey (blue), black, mahogany and tawny, and the lighter and darker shades of these colors. All colors may be reverse brindled. There may be solid white markings on the chest, throat area from chin to chest, underside of the body, penis sheath, backs of the pasterns, and on the toes. There may be white hairs at the back of the wrist and around the stopper pad. 
Disqualification: 
Solid white markings on the head, and extensive solid white markings on any parts of the body not mentioned above.  

Gait: 
The Neapolitan mastiff's movement is not flashy, but rather slow and lumbering. Normal gaits are the walk, trot, gallop, and pace. The strides are long and elastic, at the same time, powerful, characterized by a long push from the hindquarters and extension of the forelegs. Rolling motion and swaying of the body at all gaits is characteristic. Pacing in the show ring is not to be penalized. Slight paddling movement of the front feet is normal. The head is carried level with or slightly above the back.  

Temperament: 
The Neapolitan Mastiff is steady and loyal to his owner, not aggressive or apt to bite without reason. As a protector of his property and owners, he is always watchful and does not relish intrusion by strangers into his personal space. His attitude is calm yet wary. In the show ring he is majestic and powerful, but not showy.  

Faults: 
The foregoing description is that of the ideal Neapolitan Mastiff. Any deviation from the above described dog must be penalized to the extent of the deviation.  

Over All Disqualification's:  
Absence of massiveness.  
Absence of wrinkles and folds  
Absence of dewlap  
Lack of tail or short tail, which is less than 1/3 the length from point of insertion of the tail to the hock Solid white marks on the head and extensive solid white markings on any parts of the body not mentioned above. 

***Because this standard uses wording, phrases and format required by the AKC,  
the verbiage differs somewhat from the standard used by the FCI. However, as noted, this standard is internationally acknowledged by breed experts as accurately and correctly representing the Neapolitan Mastiff.  *Taken off the USNMC Web Site*