American Mastiff Breed Information

BullmastiffThe American Mastiff is an enormous, powerful canine that is very distinctive and easy to identify from most other breeds.

The typical Mastiff includes a wide head and bulky build with rectangular ears and dark eyes. Ears sit high on the head and are rounded.

A medium-size muzzle is well proportioned and usually includes a black mask. The thick neck arches slightly, and the chest is broad and deep, descending to elbow-level.

The hind legs stand parallel to one another with a wide space in between and arched loins. Forelegs are also wide-set.

American mastiffs are usually born with a dark coloration that becomes lighter as they age.

American Mastiff Temperament and Personality

American Mastiff’s temperament includes devotion and loyalty. The breed adores children in the household and is generally not aggressive unless it feels that its pack is threatened. 

They are courageous guardians that will go to great lengths to defend if necessary.  The breed also has a very gentle, kind side that makes it attractive to many.

American Mastiff puppies that are properly trained and cared for will grow into wonderful pets of enormous size.

Potential owners should also note that American Mastiffs require strong leadership to manage.

Height and Weight of the American Mastiff

The American Mastiff is a large breed working dog. You need to know if you have the space to handle a dog of this size because they are giant.

American Mastiff size usually comes to a height of 28 to 36 inches (65 to 91 cm).

American Mastiff weight falls between 160 to more than 200 pounds (72 to 90 kg) for males and 140 to 180 pounds (63 to 81 kg) for females. 


American Mastiff Coat

The American Mastiffs have a very short coat. It is quite dense, and they will shed a lot. To help manage all the shedding, you can regularly brush your dog.

The look and appearance of the American Mastiff is a lot like the English Mastiff. They do come in quite the same colors as well.

American Mastiff Health Problems

American Mastiff breeders should warn potential owners that this dog is prone to the health conditions that are typical in other large size breeds. Overall, American Mastiffs are generally healthy canines.

There are a few things you should keep in mind when owning a large breed dog because they are just naturally prone to certain things for being so large.

Bloat is extremely common with large dogs; they will eat and eat and basically won’t stop. You need to feed large breed dog’s multiple small meals throughout the day to combat this.

Bloat makes the stomach twist, which can actually be life-threatening, so keep that in mind and try to make your dog’s meals smaller.

Large dog breeds can also get hip and joint pain. They need soft beds to lay on instead of the hard floor. This will help with any joint pain they may experience.

If you are ever in doubt or worried, make sure you consult your local veterinarian.

Living Conditions

American Mastiff puppies will grow into large canines, which can be problematic in tight living quarters. The breed can thrive in an apartment or condo setting as long as they are given adequate exercise each day.

A fenced-in yard is ideal. The typical Mastiff will become lazier as he or she ages, and they prefer to remain inactive and relax while indoors.

American Mastiff Exercise

Adult American Mastiffs tend to be couch potatoes. This can lead to weight gain if the owner is not careful. 

Daily walks are recommended to help engage the dog mentally and physically and to keep him or her in good shape.

Feeding the American Mastiff

The American Mastiff is a huge dog breed and needs a lot of food to keep your dog’s energy level. Your dog needs four cups of high-quality dry dog food broken up into smaller meals throughout the day.

Depending on what brand of dog food you purchase will affect your daily cost, but it will be somewhere around $2.50 to $3.00 a day on food for your dog.

When your dog is a puppy, you should feed your American Mastiff a large breed puppy food until your puppy reaches the 18-months of age.

After that, your dog can then switch to a regular adult large breed dog food. Remember to break the meals up throughout the day to decrease the risk of bloat in your dog.

Life Expectancy of the American Mastiff

American Mastiff life expectancy ranges from 10 to 12 years on average.

Depending on the health of your dog will ultimately determine how long they will live. As long as your dog is happy and healthy, I would not dwell or worry about this.


American Mastiffs have short, smooth coats that are very easy to brush. A firm bristle brush should be used along with a towel or soft cloth to enhance shine.

This breed ranks as an average level shedder. Regular brushing is recommended to keep loose hairs off of carpets and furniture.

Other than that, make sure you are trimming the nails when necessary if your dog is not wearing them down themselves.


Fredericka Wagner of the Flying W Farms began breeding an Anatolian Mastiff with an English Mastiff in an effort to create an improved version of the breeds.

Her goal was to reduce drooling habits, increase life span, and reduce the risk of hip dysplasia.

Her selective breeding program created the American version, which looks much like its English cousin. American Mastiffs were recognized as an official breed by the Continental Kennel Club in 2000.

What Colors Do They Come In?

You will find that this breed is very similar to the English Mastiff, so they look very similar and have the same colors. Some of the colors are:

  • Brindle
  • Tan
  • Fawn
  • Apricot
  • Sometimes White Markings

You will most likely get a puppy with a back nose and either brown or amber eyes. You know how this breed has the black mask face meaning it has the signature dark face with the tan body. That is one way to know you have a real American Mastiff.

Good for First Time owner? Training?

Potential new owners looking for American Mastiff breeders should be aware that due to its enormous size, this breed is not recommended to the inexperienced. 

Puppies quickly grow into huge canines that take up a lot of space and possess a lot of muscle. They are generally calm, happy dogs, but they still need strong leadership and someone who can handle a sizeable canine.

I would not recommend you getting one of these big dogs if you live in an apartment or small townhome. They need a lot of space to roam around, plus they do have a very loud bark that could upset neighbors.

Before searching for American Mastiff puppies for sale, it is vital that a potential owner familiarize themselves with the breed.

American Mastiff Litter Size

The average litter that a female American Mastiff can have is around three to six puppies. A female can have a litter around every year and a half.

Remember, this is a very big breed dog, so the puppies will be born quite big.

american mastiff puppies

American Mastiff Puppies

American Mastiffs can be quite hard to find a breeder for, but if you look hard enough, you can find a few.

Most breeders are registered with the American Kennel Club, and that will be one way you know you are getting a reliable breeder.

You can expect to spend around $1,200 to $1,500 for a puppy. Some breeders charge more, but they also get the puppy microchipped, first vet visit, and registration papers.

Training the American Mastiff

The American Mastiff is a naturally stubborn breed. They can have trouble following basic commands, so you may need to find an experienced trainer that can teach your dog some great commands.

This breed has great intelligence in other areas because this type of dog is actually a working breed dog. In other areas, you will need a trainer to help get your dog to learn basic commands and tricks.

Make sure you still socialize your dog and get your dog used to children, other animals, and strangers. Always use treats as a positive reinforcement to help with potty training and basic commands.

Close Relatives of the American Mastiff

Below you will find a few relatives that are closely similar to the American Mastiff, they are:

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