The Complete American mastiff Guide

You didn’t land on the American mastiff by accident. This is a breed people seek out, and for good reason. The dry-mouthed giant, calm, devoted, and drier than the English, and all the gentle giant, less of the drool, they’re a natural fit for experienced large-dog owners with space who want a devoted, calm giant with a longer lifespan and less drool who want a massive, gentle, and devoted companion with the dry mouth and extended lifespan the English Mastiff lacks. Let’s dig in.

What are the characteristics of a American mastiff?

Think you know what you’re getting into with a American mastiff? These scores will either confirm your suspicions or give you something to think about. Either way, good to know now.

Training

Trait	Score	What does it mean?
Trainability	3 out of 5	Intelligent and cooperative. Early training is essential given their eventual size
Obedience	3 out of 5	Responds well to consistent gentle handling established early
Focus	3 out of 5	Generally attentive in training contexts
Stubbornness	2 out of 5	Gentle and cooperative when training is consistent

Friendliness

Trait	Score	What does it mean?
Good with family	5 out of 5	Deeply devoted to their family
Good with children	4 out of 5	Patient and gentle with children. Size supervision is essential
Good with strangers	3 out of 5	Calm with familiar people. Watchful with strangers
Good with other dogs	3 out of 5	Generally good with other dogs

Adaptability

Trait	Score	What does it mean?
Apartment living	1 out of 5	Not suited to apartment living
Cold weather	4 out of 5	Handles cool weather well
Hot weather	2 out of 5	Heat management is important given their size
Routine flexibility	2 out of 5	Needs a cool, spacious environment
First time owner	2 out of 5	Better for experienced large-dog owners

Physical needs

Trait	Score	What does it mean?
Energy level	2 out of 5	Low energy. Deliberate and calm
Endurance	1 out of 5	Not built for sustained physical exertion
Exercise needs	2 out of 5	Needs 20 to 30 minutes of gentle daily exercise
Mental stimulation	3 out of 5	Intelligent and observant
Grooming needs	3 out of 5	Short dense coat that sheds moderately

Personality

Trait	Score	What does it mean?
Playfulness	3 out of 5	Playful in a slow, gentle way
Affection	5 out of 5	Deeply warm and affectionate
Loyalty	5 out of 5	Total devotion to their family
Independence	3 out of 5	Self-sufficient. Handles alone time
Alertness	3 out of 5	Alert and calm

Behavior

Trait	Score	What does it mean?
Barking tendency	2 out of 5	Barks rarely. Deep and infrequent when it occurs
Digging tendency	1 out of 5	Not prone to digging
Chewing tendency	2 out of 5	Low chewing in adults
Prey drive	2 out of 5	Low prey drive
Guarding instincts	4 out of 5	Their size alone deters. Quiet and instinctive guarding

What are common health issues of a American mastiff?

Like all breeds, American mastiffs are prone to certain health conditions. Here’s what to keep on your radar.

What are the recommended health tests for American mastiffs? 

Your American mastiff can’t tell you when something’s off. That’s what these tests are for. Here’s what vets typically recommend for them.

• OFA hip and elbow evaluation
• Cardiac evaluation by a board-certified cardiologist
• CAER ophthalmologist eye exam
• OFA thyroid evaluation

Do American mastiffs need pet insurance?

We’ll let the numbers do the talking, but spoiler: a lot of American mastiff owners are really glad they had coverage.

Those numbers aren’t hypotheticals. They’re real claims from real American mastiff owners in 2025.

The right pet insurance means you’re making decisions based on what your dog needs, not what you can afford.

With Lemonade, you can build a plan around your American Mastiff specifically. Start with accident and illness coverage as your base, then add on what makes sense for your dog, things like physical therapy, dental illness, or behavioral treatment, and skip what doesn’t. Coverage applies to conditions that aren’t pre-existing (AKA, a condition that occurs after your policy is active and your waiting periods have passed), and you’ll know exactly what’s included before you commit. No fine print ambushes, no surprises at claim time.

And when you do need to file? You can do it in the app in minutes. No paperwork, no hold music, no waiting around.

American mastiffs are worth protecting with proper coverage. Here’s how to do it right.

How much does pet insurance cost?

The cost of your premium is personal. It depends on your American Mastiffs age, your location, and what you add to your plan. That said, here’s a realistic look at what other American mastiff owners pay with Lemonade:

Age	Average monthly premium
1 year old	$70-$75
2 years old	$70-$75
3 years old	$80-$85
4 years old	$50-$55
5 years old
6 years old	$55-$60
7 years old	$75-$80

Not sure if Lemonade is the right fit for your American Mastiff?

See how we stack up. Compare pet insurance options side by side and find the coverage that fits your American mastiff and your budget.

History of the American mastiff

The American Mastiff is a relatively newer breed developed in the United States by Fredericka Wagner of Flying W Farms in Ohio, beginning in the 1980s. Wagner's goal was to create a Mastiff-type dog with a drier mouth than the English Mastiff, as the English Mastiff's heavy drooling was a significant barrier for many potential owners. She crossed English Mastiffs with Anatolian Shepherds to reduce the lip and jowl structure that causes excessive drooling while retaining the gentle temperament and massive size. The resulting American Mastiff is generally drier-mouthed, longer-lived, and slightly lighter than the English Mastiff. The Continental Kennel Club recognized the American Mastiff. The breed is not recognized by the AKC. Breed enthusiasts argue the American Mastiff retains all the character of the English Mastiff while addressing the drooling that many owners find difficult to manage.

Caring for a American mastiff

Training

Training a American mastiff is straightforward, but it’s worth the effort. They are gentle, willing to please, and moderately food motivated, which means training is usually smooth when kept calm and positive, though their large size makes early work essential. Positive reinforcement with treats and calm, consistent expectations starting from puppyhood tends to work best, and getting started early makes a real difference.

Whether you’re starting from scratch or leveling up, these are worth the read.

Grooming

American mastiffs have a short, dense coat that requires minimal grooming. Weekly brushing with a rubber curry comb or soft bristle brush is all the coat needs, and the occasional wipe-down keeps them looking their best. Facial wrinkles and jowls require regular cleaning to prevent moisture and bacteria buildup.

From nail trims to professional care, here’s everything you need to keep your American Mastiff looking (and feeling) their best.

Exercise and mental stimulation

American mastiffs have moderate energy levels and need 45 to 60 minutes of exercise each day to stay happy and healthy. Leisurely walks, gentle fetch, and short outdoor exploration are all great ways to burn through that energy. But physical exercise is only half the picture. American mastiffs are moderately intelligent dogs, and mental stimulation is just as important as the miles you put in. Without it, they become restless and destructive given their considerable size despite their generally calm nature. Puzzle toys, training sessions, and scent work are all solid ways to keep their brain engaged between walks.

Here’s how to build an exercise routine your American mastiff will actually love.

Nutrition

American mastiffs are giant dogs with moderate energy, so they need a diet to match. Most adults do well on around 2,300 to 3,000 calories a day, spread across two meals. Depending on what you’re feeding them, expect to spend around $95 to $140 a month on food. Not the cheapest line item, but not the most expensive either.

What goes in the bowl is your call, and your vet’s. Kibble, raw, fresh, or a combination: there’s no single right answer. Focus on quality ingredients, the right portions for your dog’s age and activity level, and you’re most of the way there.

Get the full picture on feeding a American mastiff here.

American mastiff costs and adoption

What does it cost to bring home a American mastiff?

Before your American mastiff even sets a paw in your home, there are some one-time costs worth planning for. Here’s what to expect upfront.

Category	Cost Range	Details
Adoption (Reputable breeder)	$1,500-$4,500	Health testing, vaccinations, early socialization, pedigree
Adoption (Rescue/shelter)	$50-$300	Basic veterinary care, spay/neuter, temperament evaluation
Initial veterinary care	$300-$700	Exam, vaccinations, spay/neuter if needed, microchip
Essential supplies	$200-$500	Crate, bed, leash, collar, food bowls, toys
Training classes	$150-$300	Basic obedience, puppy socialization

Unexpected costs have a way of showing up in year one more than any other. A starter emergency fund alongside a solid pet insurance plan is the best way to make sure they don’t catch you off guard.

What does it cost to own a American mastiff each year?

Once you’re past year one, ownership costs settle into a more predictable rhythm. Here’s what most American mastiff owners spend annually, though keep in mind these numbers can vary quite a bit depending on where you live, your dog’s individual health needs, and the choices you make along the way.

Category	Annual cost	Details
Food and treats	$1,300-$2,200	Based on the recommended portion for your American mastiff
Routine Veterinary Care	$500-$1,000	Wellness exams, vaccinations, dental care
Professional Grooming	$100-$300	Every Every 6 to 8 weeks, Short coat sheds moderately and requires minimal professional grooming.
Toys and Supplies	$200-$400	Replacement items, mental stimulation toys

What are popular American mastiff names?

We’ve crunched the numbers, and found the top 10 most popular names for American mastiff we see at Lemonade.

More names where those came from. If none of these are clicking, we’ve done the digging for you. Go find the one that sticks.

American mastiff puppies

Puppy veterinary needs

The first year matters a lot. What happens between 8 weeks and 12 months shapes who this dog becomes. Here’s what to focus on.

The first few months are the most important window for your puppy’s health. Core vaccines start at 6–8 weeks and continue through 16 weeks. After that, its annual boosters and routine screening as they grow into adults.

It’s a lot to keep track of. That’s why we made it easy.

Puppy socialization

American mastiff puppies are calm, devoted, and genuinely massive, with a practical dryness that makes giant-breed ownership more approachable. That all the gentle giant character with meaningfully less drool than the English Mastiff is part of what makes them space, giant-breed budget, early training, heat management, bloat awareness, and cardiac monitoring, and it’s also why early socialization matters so much.

Between 8 and 16 weeks, get them in front of as much variety as possible. Different people, animals, sounds, surfaces, and locations. Keep every experience positive. Puppy classes are great for this: supervised, controlled, and full of exactly the kind of novelty a American mastiff brain needs to learn that the world is mostly fine.

Where are American mastiff’s most popular in the United States?

Based on Lemonade’s own policyholder data, American mastiffs are most popular in these five states. We’ve also thrown in a few things local pet owners should keep an eye on, so your pup can get out there and explore safely.

1. Texas

Texas heat is intense and sets in early. Hot pavement can burn paws from late spring through early fall, and heatstroke risk is high during midday walks in cities like Houston, Dallas, and San Antonio. Rattlesnakes, scorpions, and fire ants are also common hazards, particularly in suburban and rural areas.

2. Arizona

The desert heat is the biggest thing to watch year-round. Pavement in Phoenix can reach dangerous temperatures in summer, so early morning or evening walks are best for your dog's paws. Arizona is also home to rattlesnakes, scorpions, and desert toads, all of which are more active in warmer months, so stay alert on trails and in the yard.

3. California

Foxtail grass is one of the sneakiest hazards for California dogs. The barbed seeds can embed in paws, ears, and noses from late spring through early fall, so check your dog after any outdoor time. Wildfire smoke is also a real seasonal concern; when air quality alerts are in effect, it's best to keep walks short and stay indoors as much as possible.

4. Illinois

Chicago winters bring salted sidewalks that can irritate and crack paw pads, so wiping down your dog's paws after walks is a good habit from November through March. In warmer months, ticks become active in wooded and grassy areas, and the occasional coyote sighting in suburban neighborhoods is worth keeping in mind.

5. Washington

Western Washington's wet, mild climate creates near-perfect conditions for fleas year-round, and slugs in the Pacific Northwest can carry lungworm, a parasite dogs can pick up by sniffing or eating them. Eastern Washington and the Cascades bring different risks, including rattlesnakes and wildlife encounters on trails, so knowing which side of the mountains you're on matters.

Breed comparison

Already leaning toward a American mastiff? These breeds often get compared, here’s a quick snapshot of how they stack up.

Is a American mastiff right for you?

American mastiffs reward the right owner with a drier-mouthed practicality that makes giant-breed living significantly more manageable and a calm warmth and size that anchors a home like few breeds can. They just need space, early training, giant-breed veterinary cost, heat monitoring, bloat awareness, and cardiac screening in return. If you’re ready for that, you’re ready for a American mastiff. Make sure they’re protected from day one.

A few quick words, because we <3 our lawyers: This post is general in nature, and any statement in it doesn’t alter the terms, conditions, exclusions, or limitations of the policies issued, which differ according to your state of residence. You’re encouraged to discuss your specific circumstances with your own professional advisors. The purpose of this post is merely to provide you with info and insights you can use to make such discussions more productive! Naturally, all comments by, or references to, third parties represent their own views, and Lemonade assumes no responsibility for them. Coverage may not be available in all states. Please note that statements about coverages, policy management, claims processes, Giveback, and customer support apply to policies underwritten by Lemonade Insurance Company or Metromile Insurance Company, a Lemonade company, sold by Lemonade Insurance Agency, LLC. The statements do not apply to policies underwritten by other carriers.

Insurance claim data is based on Lemonade pet insurance claims that were settled and paid in 2025.
Average insurance premium data is based on Lemonade’s internal data and reflects the average premium over the last 12 complete months, accurate as of June 2026.
Top pet names are sourced from Lemonade’s database of pet names associated with submitted quotes and purchased policies.
Top states for each breed are based on the number of active Lemonade pet insurance policies for that breed in each state as of June 2026.