American Mastiff Information

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The American Mastiff is a large, powerful dog with a wide, heavy, rectangular-shaped head and a powerfully muscular build. The breed has a deep, rounded chest and well-sprung ribs. Their limbs are well-built, straight, and well-muscled, and their burly necks are thick and slightly arched. American Mastiffs have a long tail that reaches the hocks, and a pair of high set ears that are semi-round in shape. Their medium-sized muzzle is well-proportioned and features a black nose. American Mastiffs have teeth that close in a scissors bite and dark, amber-colored eyes. American Mastiff puppies are born darkly colored, and as they get older they become lighter. The breed’s coat can vary slightly in color, but is usually a light fawn that may or may not have some white markings.

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This breed also comes in a blonde brindle coloring with a black mask.

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American Mastiffs make excellent family pets as they are terrific with children and hopelessly devoted to their owners. They are dignified, mellow, calm, and quiet. While American Mastiffs are very protective, they are never aggressive. Rather, they make excellent watch dogs and only attack if their families (especially children) are in danger. American Mastiffs are social, wise, and gentle with people, and they are very patient with small children and other animals.

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28 – 35 inches
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140 – 200 pounds
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General Health

American Mastiffs typically live for 10 to 12 years.

American Mastiffs do well in an apartment setting with daily exercise. As they grow older and tend to become a little lazy, a daily walk will do, or a run in a fenced in yard. They are relatively inactive indoors.

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The American Mastiff was developed by Fredericka Wagner. She constructed the breed in Piketon, OH after crossing an English Mastiff with a dog thought to be an Anatolian Mastiff or Anatolian Shepherd. After much selective breeding, Fredericka Wagner was able to create Mastiff puppies with a tight lower lip line and a dry mouth.

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American Mastiffs have a short-haired coat that is comparatively easy to take care of. They require regular brushing and their coat can be wiped down with a cloth for a glossy sheen. They require baths and dry shampoos only as necessary. American Mastiffs are average shedders.

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Ideal Environment

The American Mastiff can do acceptably in a small household or apartment if he is sufficiently exercised. They are comparatively inactive indoors, so their ideal living conditions would consist of at least a small yard. The American Mastiff has a propensity to become lazy, but they will have a better quality of life if exercise is initiated.

The American Mastiff is a dog that needs a job and daily exercise. Mastiffs also need rules, guidance and demand respect. With these applied you will have a great dog. If not, you may experience trouble.

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Dog Training!

If you're having problems training your dog or getting control, you should read our review of Adam will do whatever it takes to help you whip your dog into shape. I've used them to help with my Great Dane as well as help friends train their dogs. It's the first place I go to help answer users Questions. Many training issues are too extensive to answer in this forum, which is why I refer a lot of the load to his site. Update: I've been using and recommending DogProblems for three years now. I, as well as my users, value the techniques we've learned. I get weekly emails from users who have become better owners from the information they received.

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American Mastiff Q&A

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I am looking to adopt an AM in 2008. I had a St. Bernard for 9.5 years - he was an energetic puppy but was not the type to chew on furniture, etc. What is the energy level of a properly exercised AM?

American Mastiff puppies have the energy level of any puppy. As adults, American Mastiffs, like their English Mastiff cousins, can turn into couch potatoes if you let them. They don't require a lot of exercise, but a nice walk is always enjoyed. My American Mastiff loves to chase a Frisbee or his Jolly Ball thrown across the yard. Wishing you the best with your future American Mastiff! They're awesome dogs!


I am looking into getting a AM but have never owned one. I worked at Boxer breeding kennel for a number of years so being around dogs is not an issue. But I'm not very sure as to where I can find a AM breeder. I dont want one for show, just a pet/member of the family. And roughly what kind of prices will I be looking at for buying the dog, and roughly how much food they eat?

We got our puppy from Frederica at Flying W Farm, great breeder. Pricing just changed, have a look at their site. Our 12 week old female puppy eats about 6-7 cups of quality dried food and a chicken leg every day.


We have a 11 week old AM. We know that obedience training is important but would like to know at what age ( or problems exhibited) to start this training?

We are starting ours at 12 weeks, right after the last puppy shot.


We have a 1 year old male American Mastiff named Leo. Think we need to change dog food-possible allergy to the current food. What is the most recomended dog food(besides home made) to give AM's? (note-he eats about 5-6 cups per day)

You'd want any high quality, low protein and fat food. My first was a fan of Iam's, but there's also a fantastic option made through a breeder in Southern California that will ship it out, and it's been adding years to the lives of giant dogs. They even have a picture of a sixteen year old Great Dane. I think it's called gentle giants.


Wanted to know how well AM's do with the addition of a new AM puppy introduced as a part of the family? Thinking about getting a female as a sibling/playmate for our male(currently 1yr old) he's very territorial when it comes to our daughter and myself and stands between us and other dogs or strangers. possible problems?


I had a AM growing up and would like to get another one. I have 3 kids, and another dog. Would this be a problem? I am wanting a Male Puppy! Is there a AM rescue around Oklahoma??


My daughter is afraid of dogs, and my son is hollering he wants a puppy, but I have been reluctant because of my daughter, would it be a good idea for us to have am American Mastiff puppy while she is young and can get used to it or should we wait till she is much older? I have always been told that if exposed to animals children ar less likely to be afraid, and I would like a puppy myself. So what would be a good thing to do?

If your daughter is afraid of dogs an American Mastiff is not one to consider. The AM's need a strong figure and tend to take advantage of the less confident.


i grew up having a couple of mastiffs when i lived with my parents. now i have my own place and want another. but I like to backpack and go hiking etc, how well will a mastiff do if i take them hiking or backpacking with me?

The AM's can be good hiking dogs once they have fully grown and matured...but that can take roughly 2 years. Any type of strenuous activity before maturity can seriously damage the dog's bones and joints and you could end up with a young AM suffering from arthritis and possibly other problems. Also, even when the dog is full grown, AM's have the tendency to get be prepared to only walk him as far as you'd want to carry him back if need be. And ideally, a fully matured AM will only need a short walk a day (approx. a mile), so you might want to consider another breed if hiking/backpacking is of large importance.


How intellegent are the dogs?

I have a 4 month old, male, AM and he is wonderful and very intelligent! It is very hard to look at his like he is a puppy because he is so laid back, doesn't chew on anything other than his toys, is already housebroken (was at 10 weeks) and not to mention the fact that he is 60 lbs already! He is currently going through his adolescent phase where he is testing his boundaries...but he'll get through it and be more obedient. He was very easy to train on basic commands (sit, down, etc.)...he learned them after only a few tries. Hope this helps :)


Will a AM make a good fist dog?? Also are they known to be dominante?

It all depends on what type of dog you want for your first one we have an AM and absolutely love her. They are very trainable and affectionate animals but as with ANY dog out there if they do not have someone in there home that leads them they will assume the role as leader themselves. Are they a fiercely dominate breed that will challenge you every day? No. Just remember they are very big and be prepared for your coffee table (we no longer have one) to be swept clean every time they enter the room.

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