Why Are Mastiffs So Big?
Their Ancestry Holds A "Big" Clue

by Ken Alden

So why are Mastiffs so big? With this breed being among the heaviest and largest dog breed in the world, there is varying information concerning why these dogs are so large, and this has many confused. Well, there’s no need to continue to wonder, because we have done the research to find out the exact reason for the Mastiff’s unusual size.

Why Are Mastiffs So Big?

Mastiffs are large due to genetics. They are descendants of the Molossus, another very large dog breed. The Mastiff breed has been bred purposely over the years for guarding livestock from predators such as bears and wolves, so the larger the breed, the better. They have remained large ever since. 

Continue reading for more information about why Mastiffs are so large in addition to other interesting information about the giant breed. You won’t want to miss any of this information...Read More Below

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German Mastiff Great Dane and young girl

The Giant Mastiff 

The mastiff is an extremely large dog breed, and the reason why becomes clear when you take a look into the dog’s history. 

As mentioned a bit earlier, the Molossus is the ancestor of the Mastiff. The Molossus is another extremely large dog breed. So, genetically, the Mastiff was born to be large. It all started in the DNA.

In addition to its genetic predisposition to being a large breed, the Mastifas selectively bred to continue to grow larger over time. Now the dog is absolutely massive. Adult male and female Mastiffs are generally 28–36 inches (70–91 cm) tall. Male Mastiffs weigh between 150 and 240 lbs while females weigh between 120 and 200 lbs. 

The Mastiff’s Role Over Time 

Mastiffs have been around for more than 2,000 years, and people think that they originated in Asia and were brought to England. It’s in England where the dog became known as the England Mastiff. 

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Due to the Mastiff’s size, the breed has been used as a protector over the last few thousand years. They were used as guardians for important possessions. Livestock needed protections from wolves, bears, and other predators, and Mastiffs were used as protectors.

Back in the times of the Romans, Mastiffs were noticed because of their sheer size and their ability to take charge in dangerous circumstances. Not only were they used for personal protection, they were used as entertainment. They were used in fighting rings, where they fought bears, lions, and other predators in front of an audience.

Around the 1500s and 1600s in England, the Mastiff had multiple duties, which are listed below: why are mastiffs so big?

  • The mastiff was used as a hunter. They hunted alongside human hunters. 
  • The mastiff was a watchdog, often used to protect property.

Over time, people’s needs changed, and they became more advanced. No longer did they need Mastiffs to help them hunt for food in the wild. Around the 1800s, the Mastiff took on a different role- a role that they continue to play today. The Mastiff took on a role as a companion, and the public began to see the breed as a gentle giant.

The Big Mastiff As A Pet  

If you are considering bringing a Mastiff home, or are interested in learning more about how the Mastiff is as a pet, this section is for you. 

Though the Mastiff is huge and appears to be domineering and even frightening, the breed is exceptionally mild-tempered. Some say that this breed is one of the most calm, sweetest breeds, but don’t forget that this breed can protect the family if a dangerous situation ever presented itself. 

The Right Household for a Mastiff 

The dog would be a good pet for a household that doesn’t have small children. Why? Because, though the Mastiff is mild-mannered and loveable, it can be very easy for your Mastiff to accidentally run over your child while playing or simply going from one room to another. For this reason, a household of adults and older children is the optimal household type for the Mastiff.

A Mastiff can live anywhere, be it a large estate, an everyday home, or a city apartment. No matter where home is, this breed will be fine, as he is a homebody. He loves to chill out at home with his humans.

Mastiffs do well when they are around people. This keeps them from getting bored and tearing things up or having mood issues. For this reason, people who travel constantly, or are never home for another reason, should not get a Mastiff. They need regular contact with their owners. 

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The Not-So-Awesome Side of the Mastiff 

Nothing is perfect, Mastiff included. There are some qualities about the breed that some people find unpleasant. With their big size comes big unpleasantness. Let’s go through these here. 

1. Whenever a Mastiff shakes his head, drool flies in all directions. No person or surface is safe. You’ll need to be on the lookout and clean up whenever your dog feels the need to shake. 

2. He farts...a lot. Luckily, this can be remedied with dietary changes. Ask your local vet for advice on food that satisfies his nutritional requirements but won’t cause him to pass gas incessantly. 

3. He snores loudly. This may not bother everyone, but if you are someone who likes a quiet home, you may have an issue with a sleeping Mastiff. 

4. His size can be a hindrance. You may not realize how much a Mastiff’s size can complicate things. You have to ask yourself whether you’ll be able to transport your Mastiff to the vet or help him if he gets sick or injured. 

5. Exercise can be tricky. Your mastiff should get regular exercise. Every day, he would be let out of the house to get some physical activity. But keep in mind that, since the Mastiff is so large, he could overheat quickly, becoming over-exhausted. You’ll need to keep a close eye on him to make sure that he’s okay. 

6. He may not live long. The lifespan of a Mastiff is a short 6-10 years, and this is thought to be because of his large size. 

Determine if you can live with all of the above quirks that go along with owning a Mastiff. Be informed that the unconditional love and protection that this breed offers more than outweighs the difficult characteristics of the breed. 

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Wondering just how big some mastiffs get? This fascinating article of ours dissects each mastiff variation to reveal not only what their final sizes are, but also what their life expectancy is. 

Why Are Mastiffs So Big...Some Final Thoughts

As you may already know, a Mastiff is not the easiest dog to get your hands on. They are harder to find than some of the more popular breeds (chihuahuas, German shepherds, etc.). 

You should refrain from buying your Mastiff from a puppy mill or pet store. To find a healthy Mastiff, you’ll need to find a reliable breeder. Reliable breeders will test their breeder dogs to make sure that they are genetically healthy and won’t pass on diseases to the puppies. A good breeder will also pay attention to the Mastiff’s temperaments. You don’t want to bring a habitually, angry Mastiff home. 

To find a reliable breeder, we recommend starting with the Mastiff Club Of America (MCOA) where they have breeder listings  

Call them up and interview them. Ask them every question that you can think of. Once you feel comfortable with your breeder, go and pick out your new Mastiff.

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About Author

About the Author...

Ken Alden, a dedicated Mastiff owner for over eight
years, is acclaimed for his expertise in care, grooming, and training. Read more About Me and my dog Shadow.

Learn Even More About The Mastiff Breed Here...

  1. Mastiff Guide Home
  2. Mastiff Dog Information
  3. Why Are Mastiffs So Big