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Bull Daniff (Great Dane & Bullmastiff Mix) Info, Pictures, Facts

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By Nicole Cosgrove

Bull Daniff

Height: 25–34 inches
Weight: 105–200 pounds
Lifespan: 12–15 years
Colors: Brindle, fawn, piebald, grey, chestnut, black, white, tricolored, patchwork
Suitable for: Active families, households looking for a reliable watchdog, spacious homes, experienced dog owners looking for a large dog
Temperament: Confident, affectionate, protective, reserved, calm (as an adult)

Bull Daniffs are a designer dog breed that comes from a purebred Bullmastiff mixed with a Great Dane. The result of crossing two giant working breeds, Bull Daniffs are not your average hybrid. These massive dogs can be exceptional family dogs, as long as the house is spacious enough for their giant-sized bodies. They’re known for creating strong bonds with their families and being reserved with strangers, making them ideal for families looking for a family pet and guardian in one dog.

While they may seem serious to many, Bull Daniffs also have a playful side that can make anyone laugh. Let’s take a closer look at these massive hybrids:

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Bull Daniff Puppies


Great Dane Bullmastiff Mixes are not purebred dogs, but their status as a designer dog breed has created a niche market for them.  When searching for a Bull Daniff, take your time to find an ethical dog breeder. A reputable breeder will share information regarding the puppy’s health, let you visit the facilities, and even introduce you to the puppy’s parents.

These gentle giants tend to be very affectionate and loyal. They’re protective of their family and will create strong bonds with their human companions. When they grow into adults, they lean towards having a calmer temperament.

3 Little-Known Facts About the Bull Daniff

1. Bull Daniffs can weigh over 150 pounds

Bull Daniffs come from one large breed and one giant breed, so it should be noted that Bull Daniffs can easily weigh over 150 pounds on average. If you’re looking into getting this hybrid, make sure you have the space for these dogs. They may seem calm enough for apartments, but their size alone makes apartment living almost impossible.

2. Bull Daniffs are surprisingly gentle

While some medium and large-sized dog breeds struggle to understand their own strength, Bull Daniffs are actually quite gentle. These hybrids, as well as their purebred parents, are excellent dogs for kids of all ages due to their reserved nature.

3. Bull Daniffs can be stubborn

Bull Daniffs are known for being affectionate and loving guard dogs, but they do have some stubbornness that can be difficult for first-time dog owners. Early, consistent, and confident training is needed to keep them from taking over the household.

Parent Breeds of the Bull Daniff
Image Credit: (L) BORINA OLGA, Shutterstock | (R) Al_Er, Shutterstock

Temperament & Intelligence of Bull Daniffs 🧠

Hybrids can be nearly impossible to guesstimate in terms of temperament and intelligence, so it’s hard to say what to expect with your Bull Daniff puppy. Before looking at the Bull Daniff’s personality and intelligence, let’s take a look at the Bullmastiff and the Great Dane.

Bullmastiffs are large guarding dogs, known for their reserved, calm dispositions and a keen sense of awareness. Though they can be rambunctious as puppies, Bullmastiffs calm down into a more serious dog as they age. These big dogs are affectionate and loving couch potatoes that love the spend time with their families, but they need a confident leader to prevent stubbornness and other behavioral issues. Early socialization is also especially crucial for this breed since their instinct to protect can become stronger, so it’s important to train them to act politely with new people.

Great Danes are prized for their easygoing temperaments, often called “Gentle Giants” for their gentle mannerisms. These giant canines are playful and loving, which is why they’re popular as family pets. Great Danes have an instinctual need to guard the house, but they’re nonaggressive in their protective ways. They’re smart and can pick up on obedience fairly quickly, but Danes can become stubborn if pushed too far. As with other dogs, early socialization is important to establish proper boundaries with other people and animals.

Looking at both Great Danes and Bullmastiffs, it’s safe to say that most Great Dane Bullmastiff Mixes will be natural guardians and affectionate family pets. These dogs need a confident leader to handle possible stubbornness, but they’re relatively calm and mild-mannered. Aside from testing their place in the household, they’re loyal dogs that crave attention from their families.

Are These Dogs Good for Families? 🏡

Yes. Despite their immense size and serious faces, Bull Daniffs have a playful side that makes them great for families with children. Though they don’t need hours of exercise, Bull Daniffs enjoy watching from afar to “supervise” the kids. The only potential issue is that they may become overprotective of children, especially when strangers are around.

Does This Breed Get Along with Other Pets? 🐶 😽

Yes. Great Danes and Mastiffs are not known for having strong prey drives, and the same can be said of most Bull Daniffs. As long as all pets are properly introduced, your new Bull Daniff puppy will adapt to its new brothers and sisters fairly quickly.

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Things to Know When Owning a Bull Daniff:

Food & Diet Requirements 🦴

Bull Daniffs are prone to weight problems and obesity, so it’s important to find a diet that is high in fiber. We recommend a high-quality dry kibble that is formulated for large breeds, but it’s crucial that there is enough fiber to aid in digestion. Before starting any new diet or dog food, it’s important to consult with your veterinarian first.

Exercise 🐕

Bullmastiffs and Great Danes are both known for their lower exercise needs, Bull Daniffs are big dogs that need adequate exercise to prevent weight gain and other health issues, but they’re not as energetic as other big breeds. They’ll need at least two long walks a day and some time to roam off-leash. It’s crucial not to over-exercise Bull Daniff puppies since their bones are still growing and developing.

Since Great Danes are good at tracking, your Bull Daniff may inherit this ability. Tracking can be a fun and entertaining exercise for your new dog, especially for Bull Daniffs that need a confidence boost. Consider setting up a doggy-friendly scavenger hunt that can be great for exercise, as well as sharpening your dog’s mind.

Training 🦮

Bull Daniffs thrive with a confident leader and food-based positive training, especially with Daniffs that have more Bullmastiff qualities. These dogs are sensitive and will balk at commands if they feel they’re being teased, so it’s crucial to be gentle and consistent with any training method. Stubbornness can be a real issue in a Great Dane Bullmastiff Mix if left unchecked, but patience and consistent training are the keys to successfully training these big dogs.

Since both Great Danes and Bullmastiffs absolutely need early socialization and consistent training, consider taking group-based puppy obedience classes. Not only will this teach the basics to you and your dog, but it gives your new puppy a chance to meet other dogs. If you keep struggling with your Bull Daniff, a professional dog trainer can help overcome your dog’s training or behavioral issues.

Grooming ✂️

Bull Daniffs have short coats that moderately shed, so a good brushing out once a week can help reduce shedding. We recommend a curry comb to help remove dirt and trapped fur, as well as massage the skin and coat. Otherwise, their coats are low maintenance and won’t take hours to comb. Both Bullmastiffs and Danes are prone to sensitive skin, so it’s important not to bathe them too often. If your Bull Daniff seems to be balding from excess fur loss, contact your veterinarian and keep an eye out for other spots.

Health and Conditions ❤️

It’s impossible to know what your Great Dane Bullmastiff Mix puppy may have to deal with later in life, even with purebred dogs. One way to know what you might be dealing with is to look at your puppy’s parents and their health issues, as well as look at the lineages to see what other dogs from the same bloodline have suffered from.

Another way to prepare is to look at common health issues from both the Great Dane and the Bullmastiff, though this does not guarantee your puppy will inherit any of these issues.

Common Health Conditions of Bullmastiffs:
  • Bloat
  • Obesity
  • Cancer
  • Hip Dysplasia
  • Elbow Dysplasia
  • Subaortic Stenosis
  • Chronic dry skin
  • Hypothyroidism
  • Entropion
Common Health Conditions of Great Danes:
  • Bloat
  • Hip Dysplasia
  • Wobbler’s Syndrome
  • Cancer
  • Hypothyroidism
  • Skin and coat problems
  • Cardiomyopathy
  • Eye Problems
  • Orthopedic problems

There are a few conditions that both Great Danes and Bullmastiffs suffer from, so it’s no surprise that your Bull Daniff might as well. Conditions like hip dysplasia and bloat are prevalent in both breeds, especially due to their size. Other conditions that your Bull Daniff may inherit are the various skin and eye problems from both breeds, as well as hypothyroidism. While most of these conditions are moderately serious, there’s no way to tell if your puppy has inherited them or not.

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Male vs Female

The selection of male versus female Great Dane Bullmastiff Mix should be a personal choice, but it’s best to keep in mind that male Bullmastiffs and male Great Danes have a sizeable difference compared to females of both breeds. Other than a big size difference, choosing a male or female Bull Daniff is a personal matter that should be discussed with all parties involved.

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Final Thoughts on Bull Daniffs

Bull Daniffs may be big dogs, but they’re loving and affectionate protectors of their families. These massive hybrids enjoy constant attention and affection, so they’re best for families that are home often. It’s important to remember that these dogs can easily top the scales at 150 pounds, so they do need adequate space to stretch their legs.

Although their size can be a major dealbreaker for some, they don’t have as many exercise requirements as other breeds do. If you’re looking for a calm, reserved guard dog that is also gentle and safe to be around children, the Bull Daniff will not disappoint.

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Featured Image Credit: Susan Schmitz, Shutterstock

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