All About Mastiffs

Medically Reviewed by Amy Flowers, DVM on April 16, 2022
Written by Alyssa Anderson
7 min read

Mastiffs are gentle giants in the canine world. These strong, good-natured animals are classified as being in the working group. 

English mastiffs are a specific and pedigreed breed, but there are many mastiff-type dogs around the world. They can be a useful and loveable addition to any family — as long as you’re willing to commit to their extra-large needs.  

How big do mastiffs get? Mastiffs can be startling dogs if you’re not prepared for their size. The males tend to be even larger than the females. 

Most males are at least 30 inches in height, though they can get even taller. Females reach 27.5 inches and up. 

There is a wide range of healthy weights for a mastiff. Males can be anywhere from 160 to 230 pounds. Females can be anywhere from 120 to 170 pounds. Talk to your veterinarian if you’re worried that your pet is underweight or overweight. 

Their large size means that mastiffs are more than a handful when it comes to their care. Make sure that you have enough space for them to be comfortable — both indoors and out. 

Also, keep in mind that they’ll be difficult to transport — you’ll need to think of their needs when planning to travel.  

Body shape. Mastiffs have rectangular bodies with thick muscles and strong bones. Their chests are wide and deep — reaching at least to their elbows. 

Typical mastiff traits include sturdy necks — which support large, wide heads. Their muzzles are half the length of their skull and blunt at the end. Small, v-shaped ears with rounded tips top off their heads. They’re set far apart and hang down to graze the cheeks when at rest.   

Their tails are set moderately high on their hindquarters and hang straight down to their hocks if they are not excited. 

When these physical components come together, the overall impression is one of grandeur and dignity. When they move, though, there’s an obvious clumsiness to their gait — a trait many owners find endearing. 

Lifespan. Dogs as large as mastiffs don’t live as long as smaller breeds. The average Mastiff life expectancy is six to ten years. Keep them as healthy as possible to maximize your time with your pet. 

Fur. Mastiffs have a double coat — two different layers that each have unique properties. Their undercoats are dense, short, and tight to their skin. Their outer coats are straight, rough, and only a bit longer than the undercoat. The overall effect is a short, textured coat. 

The coats come in a limited range of colors — technically described as apricot, brindle, and fawn. These are all shades that resemble light brown and tan hues. 

A quintessential characteristic of the breed is the darkly colored mask on their faces. It surrounds their eyes and encompasses most of the muzzle. A fully black muzzle is a hallmark of the breed and is required in competitive shows.  

Eyes and Expression. A mastiff’s eyes are small compared to their large heads. They’re set reasonably far back into the skull and far apart. Normally, they’re brown and the breeder standard prefers them as dark brown as possible.

A mastiff’s friendly personality should be obvious from their expressions. They have wrinkles in the middle of their foreheads that contribute to the faces they make. Mastiffs should look alert, but not predatory. 

Personality. A mastiff’s personality doesn’t always match their intimidating size. The American Kennel Club (AKC) rates them a five out of five for affection. 

Mastiff personality traits also include patience, dignity, and affability. They prefer gentle interactions with their families. 

Their combination of loyalty, courage, and a strong physique make them useful guard dogs. This is, in fact, one of the reasons why mastiffs were bred. They’re vigilant enough to stand guard over your house or livestock and large enough to actually be able to defend you. 

In general, though, the mastiff temperament is even-keeled. They’re not easily excitable. 

Grooming. Mastiffs are some of the easiest dogs to groom. You’ll usually only need to quickly brush them every few days. 

The only exception to this is once or twice a year when they go through a period of heavy shedding. When this happens, you’ll need to brush them more thoroughly to remove all of their dead hair. 

You should clean their faces regularly — especially if they’ve gotten into anything. Take special care to clean out their wrinkles, the folds of their ears, and the areas around their eyes. 

Brush their teeth daily. Also, keep their nails trimmed short — clip them as often as you see fit. 

Feeding. Mastiffs are giant breeds that grow quickly, so their nutrition is a crucial part of their health. You don’t want your dog to become too large too quickly. Control their diets and make sure that they’re nutritionally balanced — particularly during their first two years of life, when they’re still growing puppies. 

This means that you’ll want to figure out — and stick to — a feeding schedule that works for you and your pet. You also need to pay special attention when picking out your dog food brand.

Most experts recommend that you start your mastiff on an adult brand even as a puppy — unless you can specifically find a large or giant breed puppy brand. The protein percentage shouldn’t be higher than 26%, with a calcium-to-phosphorus ratio of 1.2 to 1. Without a proper calcium-to-phosphorus ratio, mastiffs tend to develop skeletal disorders while they grow.  

Don’t hesitate to talk to your veterinarian if you have any nutritional concerns while raising these dogs.   

Exercise and Mental Stimulation. Mastiffs were bred to be comfortable hanging out at home and don’t need too much exercise. Adults should get about a one- to two-mile walk on a regular basis, but puppies need much less.

If your mastiff is only two or three months old, they don’t need to walk more than half a block at a time. You also need to keep their knees safe — particularly during their first two years. Keep them from walking too far, jumping, or running up and down stairs. These activities can damage the growth plates in their knees. 

When tired, even the adults will simply sit down in the middle of the sidewalk to keep from going any farther. Don’t overtax them, or you’ll have to figure out a way to carry your massive pet home. 

One of the best things you can do for their mental and physical entertainment is to let them roam and play around your house and yard. They’re happy to be with you and will appreciate any gentle engagement.  

Veterinary visits, medications, and immunizations. Your veterinarian is the best person to determine all of the vaccinations that your pet needs, but all dogs should get a core set. 

This includes vaccinations for:

These vaccinations can begin as early as six weeks of age. There are also other, non-core vaccinations that you can discuss with your veterinarian. 

Dosages for flea and tick medications are based on your dog’s weight and prescribed as needed. Oral and skin-based applications are available from your veterinarian or other distributors.

Many of these medications can be effective against a variety of pests and parasites, so talk to your veterinarian to figure out the best one for you. At present, heartworm medication is recommended year-round in every state in the U.S.

Mastiffs are susceptible to a number of health problems. These include: 

  • Heart disease. Have your pet’s heart examined regularly after they turn two. 
  • Eye problems. Have your pet’s eyes examined regularly for any eye conditions as soon as they’re two years or older. 
  • Hip dysplasia. Your veterinarian should check your dog’s joints on an annual basis for an abnormal fit. 
  • Von Willebrand disease. This is a genetic condition that some vets can test for. 
  • Bloat. This is a condition where your dog’s stomach swells. It can be life-threatening, so be sure that you feed them safely. 

There are many other health conditions caused by this dog’s large size, so it’s important to see your veterinarian regularly to catch problems as soon as possible. 

This breed comes with a number of unique considerations that you need to keep in mind before choosing a mastiff as a pet. 

The AKC rates them a five out of five for being great with kids, but they can struggle with other dogs and strangers. 

This means that you need to train and socialize them early to make sure that everyone feels safe interacting with your pet. 

This breed needs to be handled gently. Use lots of eye contact and positive encouragement while you train them — and try not to raise your voice. Keep training sessions short and interesting to maintain their interest.

Mastiffs also drool a lot more than many dog breeds. Some owners keep wipes on them at all times to get the drool off of their dog’s faces, their clothes, and the clothes of their guests. You need to be comfortable with drool to raise a mastiff. 

All mastiffs are part of an ancient lineage that has roots around the world — including China, Egypt, and Italy. Caesar noted the ancestors of English Mastiffs when he invaded the British Isles in 55 B.C.

Throughout their history, mastiffs have been used for a variety of hunting and guarding activities including:

  • Bear-baiting
  • Lion-baiting
  • Bull-baiting
  • Dogfighting
  • Guarding homes, farmland, and livestock 
  • War — they would commonly fight on the battlefield alongside their English owners

The specific English Mastiff breed was established in the middle of the nineteenth century. One of the progenitors of this breed — named Lion — also contributed to the main pedigrees of Deerhounds and Irish Wolfhounds. 

By the first world war, the breed was almost extinct. Their numbers remained low throughout the second world war. At this point, mastiffs were probably bred with other giants — including Bullmastiffs and St. Bernards. 

Luckily, breeders were able to restore their numbers in the late twentieth century. Today, the breed enjoys worldwide popularity.