Bull Mastiff

Written by: Jamie
Updated: May 13, 2021

The Gamekeeper’s Night Dog has a short yet interesting history. Learn all about the Bull Mastiff in today’s guide below!

bull mastiff standing on rocky road

Height: Male 25-27 inches, female 24-26 inches
Weight: Male 50-59 kilos, female 45-54 kilos
Bull Mastiff Lifespan: 7-9 years
Pedigree? (registered with the KC?): Yes, this breed is registered with the Kennel Club.

Positives and Negatives

Check out the positives and negatives of the Bull Mastiff below.


  • Minimal grooming needs
  • Ideal watchdog
  • Family-friendly pet
  • Drafting dog


  • Not ideal for first-time owners
  • Prone to weight gain
  • Heavy drooler
  • Stubborn, not easy to train

bull mastiff standing on grass


The Bull Mastiff is well-balanced between protector and family pet. They make loving companions that won’t hesitate to throw themselves in harm’s way to protect their family.

Given the right leadership, training, and socialization, this breed can be an excellent addition. This explains their worldwide popularity!

Heatstroke is a condition that more commonly affects Mastiffs. In the warmer months, a dog’s walking routine should take place during the cooler periods of the day.

Typical symptoms to look out for include vomiting, diarrhoea, red gums, excessive drooling, and drowsiness. Flat-faced dogs like the Bull Mastiff, Bulldogs and Pugs are prone to heat stress.

The Bull Mastiff price starts from £1,000 upwards! A reputable breeder must be sourced. Due to their short muzzle, badly bred dogs will be prone to Brachycephalic Obstructive Airway Syndrome.

This could cause mild to severe breathing issues.

bull mastiff dog lying on the grass


The Bull Mastiff is native to England, originating during the 19th century. During this period, they were commonly kept by gamekeepers and were used to patrol and guard at night.

They would track and pin poachers who would target game on the estates of the aristocracy. Bull Mastiffs wouldn’t attack, instead, they’d wait for the gamekeeper.

This earned them the nickname ‘The Gamekeepers Night Dog’. At the time these canines had an important role as illegal poaching was an offence punishable by death.

As time changed so did the Bull Mastiffs line of work and guarding became a more popular job role.

The breed is 60% Old English Mastiff and 40% Bulldog. By the 20th century, they were becoming known as a distinguished breed as opposed to a cross.

They were recognised by the Kennel Club in 1924 followed by the AKC in 1933. Standards were officially approved in 1935 although these have been revised since.

Despite being a newcomer, this canine boomed in popularity. In 1900, the first Gamekeeper Dog Show took place.

Men were invited to test the Bull Mastiff, of course being muzzled. This allowed the breed to display its character to those potentially interested in the breed.

Today the Bull Mastiff is still used for guarding purposes, but their temperament also makes them a good family companion.

They’ve been popular in the show ring for many years but have never bagged the prize of Best in Show at Crufts or the Westminster Kennel Club.


Bull Mastiff Temperament:
The English Bull Mastiff is affectionate and loyal to all members of their household.

A fantastic guard and watchdog, this canine won’t hesitate when it comes to protecting its family!

In the home, the Bull Mastiff breed is docile and gentle, outdoors, however, they’ll be playful and boisterous. Energy levels of course vary per dog.

bull mastiff on brown grass

Dominant and strong-willed, raising this canine won’t be a walk in the park! First-time owners should avoid.

A lack of training and socialization is the prime cause of aggression in dogs. A powerful dog like this one could easily become unmanageable in the wrong hands.

A firm and experienced owner is needed. Barking isn’t a heavy trait of the Bull Mastiff.

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Are Bull Mastiffs Good with Strangers?

Due to their alert and protective nature, this breed will be reserved with strangers. Given the right socialization, they’ll accept newcomers welcomed by their owner.

If they’re comfortable they’ll even be friendly!. A well-socialized Bull Mastiff will only become aggressive in threatening situations.

Are Bull Mastiffs Good with Children?

Yes, this canine is known to be a loving addition to any family! The Bull Mastiff size tips onto the Giant scale, so there is a risk of accidental injury to smaller children.

Bull Mastiffs thrive off the extra attention! They’re playful at heart and love interactive games such as fetch. In general, older children are better suited to this breed.

Are Bull Mastiffs Ok with Other Dogs?

If socialized well, the Bull Mastiff will get along with other dogs. The breed isn’t overly sociable but will enjoy playing with other canines.

Sparks may fly between those of the same sex, especially if dominance comes into play. Throughout their lives, regular socialization will be needed to maintain a friendly personality.

A female Bull Mastiff will be easier to socialize than an intact male. Whilst the ladies can also be dominant, fights are more common to break out amongst males.


The Bull Mastiff dog needs more than 2 hours of exercise each day. They need an owner who loves the outdoors just as much as they do!

Set aside an hour for more vigorous activities. Thanks to their webbed feet, they’re excellent swimmers.

A Bull Mastiff puppy is more playful but be cautious not to over-exercise them as this could damage their growing joints.

Dog sports are a great form of activity and mental stimulation. Agility, obedience, rally, weight pulling, and tracking are all categories this breed excels in.

Bull Mastiffs are better suited to homes with gardens and can live in both the city or countryside.

bull mastiff on lawn

Recommended next: The Japanese Akita originates from the Akita Prefecture, Northern Japan and has been in existence since the 1600s.


Below are the breed-related health conditions of the Bull Mastiff:

  • Hip Dysplasia- Abnormal development of the hip joint will lead to pain, inflammation, lameness and eventually arthritis.
  • Elbow Dysplasia- This is the most common cause of lameness in large and giant dog breeds. It is caused by abnormal development of the elbow joint. Arthritis will follow.
  • Gastric Dilatation Volvulus- This health issue commonly affects large and giant dog breeds. Fast eating is one of the main causes of this condition. Food and gasses are trapped in the stomach as it twists. Potentially fatal.
  • Brachycephalic Obstructive Airway Syndrome- The short muzzle of the Bull Mastiff could see them suffer this abnormality that causes a flatter face. Breathing problems can range from mild to severe.
  • Entropion- Abnormal development of the eyelid causes it to grow inwards. The eyelashes scratch the surface of the eye causing pain, ulcers, infection, and conjunctivitis.
  • Ectropion- The eyelid appears droopy, exposing the inner tissues underneath. Affected dogs will experience dryness and irritation.
  • Persistent Pupillary Membrane- The strands of blood vessels within the eye provide nutrients for development before birth. Dog’s with PPM will still have remnants of the tissues that should’ve disappeared 5 weeks after birth.
  • Hypothyroidism- An underactive thyroid gland doesn’t produce enough hormones, thus affecting a dog’s metabolic state.

Intelligence & Training

Bull Mastiffs have a moderate level of intelligence. It’s their stubborn and independent thinking that can make training a struggle.

Experienced owners are better suited to the breed. Bull Mastiff puppies will benefit from group puppy classes. A place where they can learn commands, whilst socializing with other people and dogs.

Training should be given the moment a puppy walks into its new home. A Bull Mastiff must learn their position in the pack.

They will push boundaries testing their owner’s dominance. Be firm and consistent, immediately disciplining bad behaviours.

This breed has a sensitive personality so positive reinforcement is a better-suited training method.

bull mastiff resting in park

Thorough socialization is needed to prevent aggressive behaviour in adulthood which could be directed to both humans and dogs.

Teach obedience alongside, in a variety of different environments both indoors and outside. Sessions should never surpass 10-15 minutes as the Bull Mastiff will soon lose interest.

Owners with a little less confidence should seek professional help from a trainer experienced with large powerful breeds.

Bull Mastiffs won’t need any guard dog training as they are natural protectors. Getting a puppy into a routine is crucial as it provides a structure that undoubtedly builds their confidence.

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Like the French Bull Mastiff, this one is also a moderate shedder and is at its heaviest in the Spring and Autumn months.

Overall, their coat is low maintenance and will need brushing once a week to remove any dead hairs. Bristle and rubber brushes are the best tools to use on a Bull Mastiff’s coat.

The folds on the dogs face will need to be cleaned and kept dry. If not, bacteria could build up thus leading to infection.

Baths should be given every 8 weeks but no sooner than 6 weeks. Keep an eye on the skin for any signs of dryness. By maintaining weekly brushing, the dog’s natural oils will be redistributed over the body.

bull mastiff looking from afar

This breed is a heavy drooler just like their cousins the Italian Bull Mastiff. Keep a towel to hand and wipe their mouth after drinking and eating.

Some dogs drool more than others. If the jowls are long, expect lots of slobber!

Ear infections are common in Bull Mastiffs due to their long ears. Clean these weekly to prevent any debris and bacteria build up in the ear canal.

Nails will need a trim fortnightly if they haven’t filed naturally themselves. Teeth should be brushed at least three times a week although vets recommend this is done daily.

About the Author

Hi, I'm Jamie! I've always been around dogs and now writing about them is an absolute joy.
Read more about my story here.
Reach me at Jamie@woofbarkgrowl.co.uk or connect with me on LinkedIn below.

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