American MastiffCharacteristics, history, training and care

The American Mastiff is a giant molosser-type dog created in the USA by Fredericka Wagner at the Flying W Farms kennel. It comes from crossing an English Mastiff with an Anatolian Shepherd Dog. It is a young breed, recognised only by the American Continental Kennel Club, since 2000.

Quick facts

Common name	American Mastiff
Scientific name	Canis lupus familiaris
Country of origin	United States
Official recognition	Continental Kennel Club (USA), since 2000; not recognised by the FCI or the AKC
Lifespan	No published data for the breed; very large breeds usually live shorter lives than small ones
Size (males)	81–91 cm at the withers; 73–91 kg
Size (females)	71–86 cm at the withers; 64–82 kg
Coat type	Short, like the English Mastiff's
Common colours	No published data; it resembles the English Mastiff
Energy level	Low to medium
Suited to an apartment?	Yes, with a daily walk (Spanish Wikipedia)
Temperament	Calm, devoted to its family, protective
Tendency to aggression	Low; protective if the family is threatened
Good with children	Good, under supervision, because of its size
Good with other animals	No published data
Genetic predispositions	No specific diseases known; as with giant breeds, dysplasia and bloat

Primary category:Dog breeds
Explore this animal's categories:
Dog breeds Giant dog breeds Molossers and mastiffs

History and origin

The Spanish Wikipedia says the breed was created by Fredericka Wagner at the Flying W Farms kennel in the USA. She crossed an English Mastiff with an Anatolian Shepherd Dog. The aim, according to older descriptions of the breed, was a dog like the English Mastiff but one that drools less.

In 2000, the Continental Kennel Club recognised it as a purebred breed. Some critics regard it as merely a variety of the English Mastiff or a cross.

How the breed developed

Beginnings – Fredericka Wagner creates the breed at Flying W Farms.
2000 – Recognition by the Continental Kennel Club.
Today – A rare, young breed with few breeders.

Breed rating

Feature	Stars
Training and intelligence	★★★☆☆
Easy to train	★★★☆☆
Intelligence	★★★☆☆
Independence	★★★☆☆
Stubbornness	★★★☆☆
Behaviour and temperament	★★★☆☆
Affectionate with family	★★★★★
Friendly with children	★★★★☆
Good with other dogs	★★★☆☆
Good with cats and other animals	★★★☆☆
Loyalty	★★★★★
Tendency to be aggressive	★★☆☆☆
Tendency to bark	★★☆☆☆
Needs and care	★★☆☆☆
Shedding	★★★☆☆
Needs frequent grooming	★☆☆☆☆
Activity and lifestyle	★★☆☆☆
Energy level	★★☆☆☆
Daily exercise needs	★★☆☆☆
Suited to apartment life	★★★☆☆
Health and longevity	★★★☆☆
Life expectancy	★★☆☆☆
Predisposition to genetic diseases	★★★☆☆
Working abilities and uses	★★★★☆
Good guard dog	★★★★☆
Good companion dog	★★★★☆

Indicative rating: 5 stars means the highest level. The breed has no FCI standard and no AKC profile, and sources are scarce; the rating is only indicative and is based on the published descriptions of the breed.

Physical characteristics

It is a giant molosser-type dog, that is, a massive dog with a large head and a short muzzle. It looks very much like the English Mastiff. Females measure 71–86 cm at the withers and males 81–91 cm.

General appearance

Females weigh 64–82 kg and males 73–91 kg. At this size, the dog needs space in the house and in the car. An adult can pull hard on the lead, so teaching it to walk to heel is very important.

Feature	American Mastiff
Size	Giant
Height at the withers	males: 81–91 cm; females: 71–86 cm
Weight	males: 73–91 kg; females: 64–82 kg
Type	Molosser
Coat	Short, like the English Mastiff's

Training and socialisation

Older descriptions of the breed present it as gentle with children, devoted to its family and calm, generally not aggressive unless the family is threatened. A dog this big must still be trained from an early age, while it can still be controlled easily.

Use rewards and clear rules. Socialisation with new people, dogs and places helps it stay calm as an adult.

Tips for effective training

Start in puppyhood. It grows a great deal in a year.
Teach it to walk on the lead. An adult weighs as much as a person.
Use rewards. It responds well to gentleness.
Socialise it early. It will stay calm with new people.

Activity needs and lifestyle

The Spanish Wikipedia says it copes well in a flat if it gets a walk or a short run every day. A small yard is also enough for it. Giant-breed puppies must not be overworked: no jumping and no long runs until they have finished growing.

Activity	How often	Why it matters
Walk	daily	Keeps it fit
Short run	daily, for adults	Uses up energy
Obedience exercises	daily, a few minutes	Keeps it under control

Tips for a balanced life

Enough space in the house.
Moderate exercise for puppies.
A car big enough to carry it.

Care and health

Coat and skin care

The short coat should be brushed once a week with a rubber brush. Bathe it rarely, only when it gets dirty.

Common health problems

There are no published health studies on the breed. As with any giant dog, it is worth watching for:

Condition	Description	Common symptoms
Hip dysplasia	The hip joint forms incorrectly and, over time, arthritis develops	Limping, difficulty getting up or jumping, hip pain
Elbow dysplasia	The elbow joint develops incorrectly and arthritis appears	Limping on the front legs, especially after exercise
Gastric dilatation-volvulus (bloat)	The stomach fills with gas and may twist; this is a veterinary emergency	Swollen belly, trying to vomit without success, drooling, restlessness

Other care

Ask to see the parents' hip and elbow tests.
Do not let it run after a meal.
Go for yearly check-ups.

Diet and nutrition

A giant dog eats a lot, but needs fewer calories per kilogram than a small dog. Excess weight puts a lot of strain on its joints.

Tips for a healthy diet

The table gives a starting estimate, calculated with the formula from the Merck Veterinary Manual. The first two calorie columns show the calories per day for a healthy adult dog. The last column shows what this means in dry food with 3,500–4,000 kcal per kilogram.

Dog's weight	Calories per day (neutered)	Calories per day (not neutered)	Dry food per day (approximate)
64 kg	2,530 kcal	2,850 kcal	630–810 g
77 kg	2,910 kcal	3,280 kcal	730–940 g
91 kg	3,300 kcal	3,710 kcal	820–1060 g

Split its food into two or three meals a day.
Puppies need special food for giant breeds.
A dog is at the right weight when you can feel its ribs under the coat without pressing hard.

Foods to avoid

Some human foods are dangerous for dogs: chocolate, coffee, grapes and raisins, onions, garlic, xylitol (a sweetener used in chewing gum), macadamia nuts and alcohol.

Reproduction and development

Physical and emotional maturity

In dogs, sexual maturity usually comes between 6 and 12 months, but in large breeds it can be delayed until about two years. Very large breeds become adults only at around 2 years.

Mating and pregnancy

Pregnancy lasts about 63 days, counted from ovulation. Mating a female on her first heat is not recommended. Only healthy dogs of typical breed appearance should be used for breeding.

Caring for the puppies

In large breeds, a litter has around 7 puppies on average. The puppies grow very fast, so they need growth food suited to large breeds. Socialisation starts in the first weeks.