Bullmastiff in profile, photographed outdoors

Bullmastiff

  • Giant
  • Working Group
  • Popularity rank 78

The Bullmastiff is a giant working dog bred by British gamekeepers to guard against poachers. Loyal, affectionate, and brave, this powerful breed is a steady, devoted protector and a docile companion at home.

Height
24 to 27
inches at the shoulder
Weight
100 to 130
pounds, adult
Life expectancy
7 to 9
years, median 8
Senior from
6
years, about

Senior starts in the last quarter of a breed's expected lifespan, following the 2019 AAHA canine life stage guidelines. Individual dogs vary.

About the breed

Temperament
Loyal, affectionate, brave
Coat
Smooth, short
Origin
United Kingdom
Recognized
1934
Popularity, 2015 to 2025 Rank 78 in the latest ranking

2015: rank 43, 2016: rank 48, 2017: rank 51, 2018: rank 51, 2019: rank 52, 2020: rank 55, 2021: rank 56, 2022: rank 61, 2023: rank 60, 2024: rank 67, 2025: rank 78

2015 Lower is more popular 2025

The Bullmastiff is a giant Working Group breed. Although smaller than the Mastiff, it stands 24 to 27 inches at the shoulder and weighs 100 to 130 pounds.

The breed has a large, broad head. The dark eyes, high-set V-shaped ears, and broad, deep muzzle give an impression of intelligence, alertness, and confidence. The short, dense coat comes in fawn, red, or brindle.

British gamekeepers created the Bullmastiff in 1860 by crossing Bulldogs with Mastiffs. The goal was an extra-large dog that listened well to cues and guarded against poachers, and the breed was recognized in 1934.

Bullmastiffs are loyal, affectionate, and brave. They are docile and devoted with family but may take time to warm up to new people, which makes them a steady protector and a calm companion at home.

Temperament and needs

Scored 1 to 5 for the breed overall. Individual dogs vary.

  • Affectionate with family4 out of 5
  • Good with young children3 out of 5
  • Good with other dogs3 out of 5
  • Openness to strangers3 out of 5
  • Playfulness3 out of 5
  • Watchdog and protective nature5 out of 5
  • Adaptability3 out of 5
  • Trainability4 out of 5
  • Energy level4 out of 5
  • Mental stimulation needs4 out of 5
  • Barking level1 out of 5
  • Shedding3 out of 5
  • Grooming frequency1 out of 5
  • Drooling3 out of 5

Care

The routines that matter most for this breed. Open one at a time.

Nutrition

Most breeders advise feeding a large- or giant-breed puppy formula, or an adult food, to keep growth slow and steady, since Bullmastiffs grow very fast and rapid growth can tax their systems. Puppies stay on a large- or giant-breed puppy formula until they are 1 or 2 years old, so ask your vet when to transition to an adult formula. Keep Bullmastiffs lean, especially as puppies.

Follow the feeding guidelines on the food packaging, measure each meal, and consult your veterinarian to set the right portion. Because of the risk of bloat, also called GDV, a few mealtime habits help:

  • Feed two or three meals a day instead of one (puppies do well on several small meals).
  • Set the food bowl on the floor rather than elevated.
  • Feed multiple dogs separately to reduce stress.
  • Avoid exercise from one hour before to one hour after a meal.
  • Use a slow-feeder bowl, snuffle mat, or puzzle toy so your dog doesn't eat too fast.

Because a full-grown Bullmastiff can weigh up to 130 pounds, some may benefit from joint support or an omega-3 source such as fish oil. Always talk to your vet before adding anything to your dog's diet.

Grooming

The Bullmastiff's short, dense coat needs little care. Expect seasonal shedding, and note any unusual hair loss as a possible sign of a problem. Monthly brushing reduces shedding, and the short fur isn't prone to matting, so a professional groomer isn't needed.

Bathe only as needed, using a dog-safe shampoo. Watch the skin and coat so dryness or oiliness don't become issues, since these can relate to diet and sometimes to allergies. A balanced diet and a healthy environment matter most for coat health.

Bullmastiffs are droolers. Their deep facial wrinkles need to stay clean and dry, and their jowls may need a daily wipe-down to remove drool or bits of food. Ask your vet how often to clean the ears with an ear cleaner, since regular cleaning helps keep the ears in good shape.

Like many dogs, Bullmastiffs can develop tear staining, and wiping the eyes with a vet-recommended tear-stain remover can reduce discharge. Watch for any changes in the eyes, and keep the nails trimmed so they don't click across the floor.

Exercise

Bullmastiffs need daily exercise, with brisk walks and outdoor play their favorites. Some are more sedentary and others more active by nature, but moderate movement keeps this breed happy and healthy. They make great walking companions but do not make good running partners, because they lack the stamina for long distances.

Don't over-exercise a Bullmastiff puppy, especially during periods of rapid growth, to help protect against health problems. Secure fencing is a must for outdoor areas, both to keep the dog safely contained and to keep strangers and unfamiliar animals out of its territory. This breed needs room to move around and might not do well in an apartment or small house.

The Bullmastiff is generally calm rather than anxious or fearful. These dogs are quiet and don't bark excessively, though they will bark to alert the family when something seems off. Their ideal home has older children and a calm environment.

Training

Early training and socialization are critical for Bullmastiff puppies. The breed can be strong-willed and stubborn, especially young, and grows into a very strong giant dog that can easily knock over people if untrained. Start while the puppy is still small enough to control, since Bullmastiffs grow harder to train as they mature. For this reason, they are well-suited to experienced pet parents.

Training should be firm and gentle, with a reward-based approach. Put rules and routines in place early and hold to them as the dog grows. Many breeders encourage new owners to enroll in local puppy classes so puppies meet other dogs and owners get guidance. Puppies should learn cues such as sit, stay, and down, to walk well on a leash, and to stay calm around other dogs, adults, and children.

Bullmastiffs are smart and quick to learn, and they can do well in agility, obedience, rally, and scent work and tracking. They have a kind temperament with family, including young children, but can grow reserved around new people, so early socialization matters.

They are generally good with other dogs and can get along with other pets, but socialize them together from an early age. Supervise all interactions between children and pets. If you run into trouble, contact a certified dog trainer who uses positive reinforcement.

Health conditions

11 conditions are documented for the Bullmastiff.

A predisposition is not a diagnosis. Ask your vet which screenings make sense for your dog's age.

  • Autosomal Dominant Progressive Retinal AtrophyEyes
  • Bloat (Gastric Dilatation-Volvulus)Gastrointestinal
  • Canine Multifocal Retinopathy, cmr1Eyes
  • Dilated CardiomyopathyHeart
  • Elbow DysplasiaSkeletal
Show all 11 conditions Show fewer
  • EntropionEyes
  • Hip DysplasiaSkeletal
  • LymphomaBlood
  • Oculocutaneous AlbinismSkin & Connective Tissues
  • Progressive Retinal AtrophyEyes
  • Subaortic StenosisHeart

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