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Saint Bermastiff: The St. Bernard Bullmastiff Mix - PawSafe

Saint Bermastiff: The St. Bernard Bullmastiff Mix

Photo of Tamsin De La Harpe

Written by Tamsin De La Harpe

The St. Bernard Bullmastiff Mix

The St. Bernard Bullmastiff mix, or the Saint Bermastiff, is a giant, slobbery ball of love. It may be the size of a tank, but it has the heart of a lapdog. 

The designer dog craze started in the 1950s with the Cockapoo, reaching the height of their popularity with the Doodles. Still, new and exciting mixed breeds such as the Saint Bermastiff are increasingly common.

It is vital to understand both parent breeds’ genetics before taking on a mixed breed like the Saint Bermastiff since it can inherit traits from either or both parents. 

The term “Saint Bermastiff” is sometimes also used to describe the St. Bernard English Mastiff mix, but in this article it will be referring to the St. Bernard Bullmastiff mix. Since many designer breeds are new, the specific terms for them sometimes overlap or change.

Physical Characteristics of a St. Bernard Bullmastiff Mix

There is no doubt that a St. Bernard Bullmastiff will be one hefty mutt. 

A Bullmastiff should typically weigh 100 to 130 pounds and stands between 24 and 26 inches high, while the St. Bernard can tip the scales at between 140 and 180 pounds, with some reaching as much as 260 pounds! 

The St. Bernard also typically stands between 28 and 35 inches. This means you can expect your Saint Bermastiff to fit anywhere on the spectrum between these breeds and you will probably need to invest in an extra-large dog harness when its full grown.  

If you are trying to get a good idea of exactly how big your puppy may get, it’s best to ask to see the parents, as they will be your best indication. 

Keep in mind, the mother usually plays a more significant role in puppy size, so a larger Saint Bernard mum is likely to breed a bigger dog than a smaller Bullmastiff female. 

The St. Bernard can either have a dense, short-haired coat or a wavy, long-haired one. Both coat types are known for being heavy shedders. They can be any combination of red and white or mahogany brindle and white.

On the other hand, the Bullmastiff has a short, coarse coat with only moderate shedding levels. They are always solid colors, either fawn, red, or brindle, and have a dark face mask. A mix of these breeds can inherit any combination of these coat types or colors.

It may also inherit the Bullmastiff’s noble but watchful expression or the softer, good-natured and welcoming grin typical of the St. Bernard.


Understanding the heritage of the Saint Bermastiff’s parent breeds will help you gain insight into this dog’s nature. To do this, we need to look at the St. Bernard and the Bullmastiff histories separately.

The History of the St. Bernard

The heroic story of the early St. Bernard rescuing lost travelers in blizzards and guiding them through the hazardous Great St Bernard Pass in the Swiss Alps is perhaps one of the most famous canine origin stories.

Initially bred in a famous hospice in Switzerland for this function, the first official mention of the breed was recorded in 1703. Over the centuries, it was recorded as having rescued over 2000 lost travelers.

However, as a mastiff or molosser-type dog, the St. Bernard’s heritage predated the Swiss Hospice by centuries. They were probably first brought to the Swiss Alps as Roman war dogs during the reign of Emperor Augustus between 27 BC and AD 14.

Today, it is mostly a gentle companion dog, but its working background means it is still amenable to training.

The History of the English Bullmastiff

While the Bullmastiff shares the early ancient Roman war dog heritage with the St. Bernard, its origin is slightly less heartwarming. 

Initially a mix-breed dog itself, the Bullmastiff was created by crossing the Olde English Bulldogge — now an extinct breed bred for dogfighting and bull-baiting — with the giant English Mastiff. Gamekeepers in England who kept the parks and hunting grounds of the landed gentry needed a fast, powerful dog who could catch and pin poachers at night.

The Bulldogge was seen as too vicious and untrainable for this purpose, while the English Mastiff was too large and lumbering. A mix of 60% English Mastiff and 40% Bulldogge created the Bullmastiff, the bane of poachers throughout England.

Like the St. Bernard, today’s Bullmastiff is mostly bred as a companion or for the show ring. However, they never lost their fearless, bold nature, or their devotion to their owners.

General Care of a Saint Bernard Bullmastiff Mix


Your adult Bermastiff is unlikely to be a high-energy go-getter and will probably prefer taking long naps beside you on the couch to any strenuous activity. 

In general, their energy levels are usually low to moderate.

Food & Diet Requirements

Whenever you bring a new pup into your home, it’s best to speak to your veterinarian about what to feed them, how much, and how often.

The Saint Bermastiff is a large to giant breed. This means its diet needs to be carefully controlled to avoid excess weight that can strain its joints as well as provide extra support for those growing bones. 

Sometimes they may be prone to food allergies and need a specially formulated diet to accommodate this. 

All large and giant dogs are especially prone to gastric torsion, or bloat, which means it is best to feed your St. Bernard Bullmastiff mix smaller meals multiple times a day rather than one large meal and watch that they don’t drink too much water afterward. Also, avoid heavy exercise immediately before or after feeding.


Your Saint Bermastiff’s coat can take after either of its parents. This means it can be dense and short, less dense and coarse, or long and wavy.

Daily brushing is needed with a long-coated dog to prevent matting, while the shorter coats can mean a quick brush as little as once a week with a simple pet grooming glove. Only the occasional bath is needed. 

The St. Bernard parent will be a heavy shedder and will possibly pass this trait on. Even if they don’t, you can still expect moderate shedding from this mix. 

Neither parents are hypoallergenic, so this is not a dog for a home where someone might have allergies.

Ears should be cleaned regularly as both parent breeds are prone to ear infections. Nails should be trimmed and kept short to prevent painful breaking and cracking. 

Consult your vet about the best method of keeping your dog’s teeth clean and in good condition and remember a mastiff’s typically heavy jowls means wiping up lots of drool!

The Health of the Saint Bernard Bullmastiff Mix


Like any young dog, before they settle down around two years of age, the Saint Bermastiff might be a bit lively and rowdy as a puppy. This should be monitored since it can take up to 20 months for a giant puppy’s growth plates to close, and any vigorous exercise can cause strain and unnecessary problems later in life.

It is best to avoid activities that involve excessive running and jumping, even when they are fully grown because of the extra pressure on their joints and ligaments due to their size.

Nevertheless, that does not mean you should let your Bullmastiff St. Bernard mix get away with lounging around all day, gobbling up snacks. Inactivity can lead to obesity, which in turn creates further health problems. 

In general, your dog should be walked between 60 and 90 minutes a day, but not during the heat of the day, as they are particularly prone to heatstroke.

Health Concerns
Severe Health Problems

Hip and elbow dysplasia
Cancer (particularly, but not limited to; osteosarcoma, lymphosarcoma, hemangiosarcoma)
Gastric Torsion or Bloat
Dilated Cardiomyopathy
Subaortic stenosis
Anterior cruciate ligament rupture
Mild to Moderate Health problemsDental Disease
Bladder infections or stones
Ear infections
Demodectic Mange
Occasional Health ProblemsEpilepsy
Entropion and Ectropion
Urinary and kidney diseases      

It is best to source your Saint Bermastiff from a reputable breeder who has not bred for exaggerated features like an excessively short nose, causing breathing problems, or a wrinkly face, which may result in entropion or ectropion.

A reputable breeder should also scan the parents for hip or elbow dysplasia, as this joint condition often plagues larger breeds.

Further health concerns for Saint Bermastiff mixes include many different types of cancer, particularly osteosarcoma, which seems more prevalent in big dogs.

Further potential health problems include; dilated cardiomyopathy, a thinning of the heart muscle wall; polyneuropathy, the degeneration of nerves around the spinal cord; subaortic stenosis, which involves the aorta narrowing below the aortic valve, hypothyroidism, and epilepsy.

The Lifespan of a St. Bernard Bullmastiff Mix

A Saint Bermastiff can be expected to live between 7 and 10 years.


Both parent breeds of the Saint Bermastiff are typically eager to please their owners and surprisingly intelligent. They might not be filing your taxes, but you may be surprised at how quickly they learn to open your fridge.

They have a massive food drive, which means training with positive reinforcement should yield fast results. 

The emphasis here is on reward-based training. Even with the Bullmastiff’s reputation for toughness, these breeds are “handler soft.” This means that strong words and corrections can lead to the dog shutting down or even becoming depressed.

Despite the size of your Saint Bermastiff or its Bullmastiff parent’s fearsome reputation, this should not be considered a dangerous dog breed. 

They may also inherit a Bullmastiff’s strong guarding instinct or penchant for dominance, but this in itself does not lead to a dangerous dog. If in doubt, be sure to establish yourself as pack leader or seek help from a professional trainer and behaviorist.

Sociability with Other Pets

Your St. Bernard Bullmastiff mix can inherit its sociability from either parent. Should it get its temperament from the typically docile and calm St. Bernard, there should be few problems with other animals. 

As with any dog, problems can arise if a dog is not properly trained and socialized from a young age. This may be particularly necessary if your pup inherits its nature from its Bullmastiff parent. 

To prevent problems, in addition to socialization and training, you may want to avoid keeping dogs of the same gender together.

Suitable Home

This is a fantastic family dog, although it will do just as well with a single person or a couple of any age. 

The Saint Bermastiff usually love children but interactions should always be supervised in case they knock a child over when getting too excited. This applies to any fragile or elderly household members.

Although this is not a high-energy dog, it should have a reasonably sized yard to stroll about in. Although it will do best indoors with its family as these dogs have a strong affinity for their human pack.

The Saint Bermastiff does better in colder climates, and special care should be taken in hot areas as they do not tolerate heat well.

Cost of a Saint Bernard Bullmastiff Mix

It is hard to pinpoint the exact cost of these dogs, as intentional mixes are quite rare. In many cases, a designer dog goes for well over $1000, but as these pups are not as established as the Doodles, for example, they may go for a lot less.

A giant mixed breed with as much brawn as heart, the St. Bernard Bullmastiff mix may be the perfect dog for anybody who enjoys literal slobbering showers of love. If you own a Saint Bermastiff or know somebody that does, please tell us about it in the comments below.

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Tamsin De La Harpe


Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.

Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.