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American Mastiff: Pictures, Care Guide, Temperament & Traits

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By Nicole Cosgrove

american mastiff dog

The American Mastiffs are popular for having a drier mouth than the average Mastiff dog. They have a giant stature, wide head, deep chest, and a powerful and slightly arched neck. Despite their intimidating builds, these dogs are surprisingly calm, affectionate, and loyal.

Do they pique your interest?

Read on to learn more about their physical traits, temperament, and care needs. We will lay down the facts to allow you to decide whether the breed is ideal for your household. Let’s get started!

Height: 28–36 inches
Weight: 140–200+ pounds
Lifespan: 10–12 years
Colors: Fawn, brindle, and apricot with white markings on chin, chest & feet
Suitable for: Individuals or families with older kids willing to raise a stubborn dog
Temperament: Calm, quiet, affectionate, loyal, and protective but not aggressive

The American Mastiff was developed by crossing the Anatolian Mastiff with the English Mastiff. Unlike most Mastiffs, these dogs don’t drool much because they have firmer, tighter lower lip lines.

As a relatively new breed, the American Mastiffs were first recognized as purebred in 2000. Although they are yet to enjoy official recognition by the American Kennel Club (AKC), they are registered as purebred by various national and international bodies. They include the American Mastiff Breeders Council (AMBC), Continental Kennel Club (CKC), Backwoods Bulldog Club (BBC), and the Dog Registry of America (DRA).

American Mastiffs carry themselves with utter dignity and are calm, quiet, affectionate, and loyal. These dogs make excellent guard dogs because their size is an excellent deterrent to intruders. A face-to-face encounter with these giants with wrinkled foreheads can be startling. Fortunately, American Mastiffs are protective of their owners but are hardly ever aggressive unless highly provoked.

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American Mastiff Breed Characteristics


American Mastiff Puppies

American Mastiff puppies are born with dark fur that lightens as they grow older. Don’t be surprised if a breeder presents a dark puppy and promises you that it will become light fawn by age one. Most dogs of the breed also have white markings on the feet, chin, and chest, although they are often not apparent during puppyhood.

You should expect to spend between $1,000 and $2,000 for an American Mastiff puppy. This is not the most popular dog breed, and you won’t find many breeders with puppies in stock.

In terms of maintenance, expect to part with around $1,000 during the first year and around $750 for subsequent years.

Parent breeds of the American Mastiff
Image Credit: Left – SusImage, Shutterstock | Right – Ricantimages, Shutterstock

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Temperament & Intelligence of the American Mastiff 🧠

American Mastiffs make excellent furry companions. They are unfailingly loyal to the people they hold dear and thrive when offered the opportunity to form intense and close bonds with them. Despite their sheer size, most dogs of the breed view themselves as lap dogs and can become overly clingy.

Often, American Mastiffs maintain a docile and dignified demeanor. Like both parent breeds, they are alert, bold, and formidable protectors of their family members. Although not inherently aggressive, their strong protective instincts can get the best of them if a stranger gets too close to loved ones.

Most dogs are rarely excited to meet new faces. Still, they remain calm and cordial if well-socialized and taught to differentiate between friend and foe. American Mastiffs are an intelligent breed and can learn a great deal through regular training sessions. Beware of their stubborn nature, which can make training frustrating, especially if you fail to maintain the constant position of dominance.

Are These Dogs Good for Families? 👪

Properly trained and socialized American Mastiffs are gentle and quite tolerant of kids. They are family-oriented dogs and quickly grow fond of the people within their households. Unfortunately, their sheer size and strong protective instincts make them unsuitable for homes with young children.

A protective dog is an asset that can protect your kids from potential danger. However, American Mastiffs are loyal to a fault, and although typically non-aggressive, they can even attack your children if they play roughly. In such a situation, your pet will act as an intermediary and protect its favorite.

Moreover, you cannot rule out the risk of accidents if you pair very young children and a 200-pound dog. To be safe, only add the breed to your household if you have teens or kids above seven.

Does This Breed Get Along With Other Pets?

American Mastiffs are territorial. However, they can live peacefully and harmoniously with other pets, especially when raised together. Still, never pair dogs of the same gender. They are likelier to fight to death than accept each other’s presence.

Also, it would be best to take caution when introducing a new pet to your home. American Mastiffs are notorious for being hostile toward newcomers. Provided you take the introduction phase slowly, your well-socialized doggo can ultimately tolerate the new resident cat and perhaps even offer a paw in friendship.


Things to Know When Owning an American Mastiff

American Mastiffs are loyal and can go to any length to protect those dear to them. Apart from being highly effective guard dogs, they are highly affectionate toward their family members and can reward you with years of unwavering love and companionship.

Are you considering adding an American Mastiff to your household? Here are crucial things you should know before adopting one.

Food & Diet Requirements 🦴

For giant canine breeds like the American Mastiff, providing proper nutrition and ensuring your puppies grow slowly but steadily is crucial. The ideal food must be rich in calories and have the appropriate ratios of vital elements like calcium and phosphorus.

To be safe, feed kibble brands uniquely formulated for giant dog breeds. Also, experts recommend switching from puppy to adult food at seven to nine months to ensure your dog benefits from a higher protein percentage.

If you are unsure what to feed your dog and the ideal serving proportions, be sure to seek personalized guidance from your vet.

Exercise 🐕

American Mastiffs have a lazy streak and can cuddle with you all day if given the opportunity. They are committed “couch potatoes” that accept whatever activity level you offer. Although this also makes them adapt well to apartment living, it is crucial to encourage your pet to remain active.

Daily mental and physical stimulation ensures your pet’s health and happiness. The lack of it can lead to behavioral problems like excessive barking and general destructiveness.

Ideally, it would be best if you took one-hour moderate-paced walks around the neighborhood daily. American Mastiffs also have the stamina to go for short hikes, provided you maintain a walking pace. Beware of this breed’s risk of getting tired and overheating during long hikes. If this happens and your pet plops down and refuses to walk, you must carry him back home!

Training 🎾

American Mastiffs are relatively easy to train, provided they view you as a figure of authority. Although intelligent, they are stubborn and straight-out pick and choose the orders they want to obey. They have a particular dislike for the frequent repetition of simple commands and will ignore you if they find instructions boring. Be sure to keep your sessions short, fun, and varied.

On the bright side, these dogs are not fond of challenging their owner’s dominance. Getting things done your way is easy if you use positive reinforcement training tactics. Moreover, beware that you are dealing with a sensitive dog, so raising your voice or using other punitive measures will never yield a positive outcome.

Generally, you can teach your dog basic obedience, housebreaking, common rules of etiquette, and a few tricks. If you are looking for a furry companion that excels in agility training and will obey your every command, you’ll have better luck considering other canine breeds.

Grooming ✂️

If you fancy a dog with moderate grooming requirements, the American Mastiff is an excellent choice. Your pet only needs regular brushing to keep its coat in tip-top condition. As a heavy shedder, it is necessary to schedule three to four coat grooming sessions weekly.

Moreover, check and wipe the face wrinkles daily or after every meal. Like all dog breeds, brush your pet’s teeth every other day and clip its nails monthly.

Frequent showers are unnecessary; a bath after four to six weeks will suffice. Unlike most Mastiffs, American Mastiffs have relatively dry mouths, and you don’t have to worry about constantly wiping drool and getting rid of its stink.

Health and Conditions ❤️

American Mastiffs are healthier than their parent breeds. After all, they were developed to curb some of the health concerns prone to their English Mastiff parent. The result is a relatively healthy dog with an average life expectancy of 10 to 12 years. This is alright, considering most giant breeds hardly live past the eight-year mark.

Generally, you can expect your dog to enjoy relatively good health if you work with breeders approved by the American Mastiff Breeders Council (AMBC).

Here are some health issues you must be on high alert for.

Minor Conditions
  • Hip Dysplasia
  • Allergies
Serious Conditions
  • Cancer
  • Bloat
  • Eye Problems


Male vs Female

Mastiffs are laid-back giants that make excellent family pets. Males are considerably bigger than their female counterparts, but both are gentle and maintain dignified demeanors under most circumstances. If you must pick between the two, there are a few temperament differences you should know.

Male American Mastiffs are typically more affectionate, needy, and clingy to their owners. They are more playful and active and can show dominant tendencies, mainly if intact. Although males are also not inherently aggressive, they have greater potential to show aggression toward other dogs, especially of the same gender.

Female American Mastiffs mature faster and are generally easier to train. They are also gentler than their male counterparts and better with kids. Females are also affectionate but are more independent. They are less likely to act needy and stressed when their owners leave them for a few hours.

3 Little-Known Facts About American Mastiffs

1. They Are Fierce Protectors

The American Mastiffs are among the most popular guard dogs prized for their strong protective instinct. Still, they showcase well-balanced behavior and often prefer to stay away from conflict. They only jump to action and turn aggressive if provoked or when they need to protect a loved one.

Other traits that make these dogs excellent guard dogs are that they are always alert and attentive. American Mastiffs are also bold and rarely find any situation too intimidating. If pushed to aggression, the outcome can be disastrous.

2. They Are Incredible Gentle

Despite their giant size, American Mastiffs are soft inside. They are affectionate, calm, and sensitive. If treated harshly by someone they hold dear, they recoil and can add several stacks of stubbornness to their already headstrong nature.

Fortunately, these dogs have big hearts to match their massive size. They are capable of forgiveness, but you have to earn it. If you suspect your American Mastiff is angry at you, you can win its trust and affection by offering an irresistible treat. Forget everyday kibble and think of something yummy like a slice of liver.

3. They Can Keep You Awake With Their Loud Snores

American Mastiffs have longer muzzles than their English Mastiff parents. Still, they are considered a brachycephalic (short-faced) breed capable of keeping you up through the night because of their long, loud, and hilarious snores.

Their snores keep changing from sounding like a jet fighter taking flight to a crummy motorcycle struggling to climb a steep hill!

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Final Thoughts

American Mastiffs are massive and powerful dogs. They are calm, quiet, loving, and loyal to the core. These dogs are bold and confident yet very patient with the people they hold dear. If you have always wanted a reliable guard dog that is not inherently aggressive, it’s hard to go wrong with this breed.

So, does the American Mastiff make an ideal pet for your household? It depends.

For safety reasons, it’s best not to pair this canine breed with young kids. Also, the American Mastiff is ill-fit for clean freaks or those easily embarrassed.

Generally, these dogs do drool but not a lot like their English Mastiff parent. Their relatively short muzzles also make them prone to snoring and making unusual noises when lazing around. These dogs are also messy creatures, especially when eating or drinking, and can pass a great deal of gas. If you gracefully embrace these flaws, your pet will reward you with years of loyal companionship.

Featured Image Credit: PJW31189, Shutterstock

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