English Mastiff and Great Dane Mix: The Daniff Breed Guide

If you've ever stood next to a dog that came up to your hip and thought, "I want one of those — but bigger," the English Mastiff and Great Dane mix might have crossed your radar. Commonly called the Daniff, this designer cross combines two of the tallest, heaviest breeds in the world into a single dog that can tip the scales at over 200 pounds. It's a mix that demands serious consideration — not just because of the sheer logistics of feeding, housing, and transporting a giant dog, but because the health and temperament variables in a cross this large can be significant.

This guide breaks down everything prospective owners need to know about the English Mastiff and Great Dane mix, from realistic size ranges and generation genetics to the health screenings any responsible breeder should perform before producing these puppies.

Parent Breed Breakdown: English Mastiff vs. Great Dane

Before predicting what a Daniff might look or act like, you need to understand the two foundation breeds. Both are classified as giant breeds by the American Kennel Club, but they differ in build, energy, and historical purpose.

Parent Breed Comparison: English Mastiff vs. Great Dane

Trait	English Mastiff	Great Dane
AKC Weight Range	120–230 lb (54–104 kg)	110–175 lb (50–79 kg)
AKC Height Range	27.5–30+ in (70–76+ cm) at shoulder	28–32 in (71–81 cm) at shoulder
Build Type	Massive, heavy-boned, broad chest	Tall, athletic, moderately built
Coat	Short, straight, double coat	Short, smooth, single coat
Energy Level	Low to moderate (30–45 min/day)	Moderate (45–60 min/day)
Temperament	Calm, dignified, protective	Friendly, outgoing, people-oriented
Trainability	Independent, can be stubborn	Eager to please, responsive
Lifespan	6–10 years	7–10 years
Original Purpose	Guardian, war dog, estate protector	Boar hunting, estate guardian

Both breeds share a guarding heritage, which means a Daniff will almost certainly have some protective instinct. The difference lies in expression: Mastiffs tend to be watchful and reserved with strangers, while Great Danes are more likely to greet visitors with enthusiasm before deciding if protection is needed.

Understanding Generations: F1, F1B, and Multigen Daniffs

Unlike doodle-type designer breeds that have established multigen breeding programs, the English Mastiff and Great Dane mix is almost exclusively produced as an F1 cross. This is partly because the market for giant designer dogs is small, and partly because responsible breeding of giant breeds requires extensive health testing that limits the available breeding stock. If a breeder advertises F2 or multigen Daniffs, ask for documentation — it's uncommon enough to warrant verification.

Size and Growth: How Big Will a Daniff Get?

This is the question everyone asks, and the honest answer is: it varies considerably, even within a single litter. Because both parent breeds are giant but have different build types, a Daniff can land anywhere on a wide spectrum.

Daniff Size Range Estimates

Category	Weight	Height at Shoulder
Small end (Great Dane–leaning)	115–145 lb (52–66 kg)	28–30 in (71–76 cm)
Mid-range (balanced mix)	145–185 lb (66–84 kg)	29–32 in (74–81 cm)
Large end (Mastiff–leaning)	185–230+ lb (84–104+ kg)	30–33 in (76–84 cm)

Males will almost always be larger than females, often by 30–50 lb (14–23 kg). Growth is slow — like both parent breeds, a Daniff won't reach full skeletal maturity until 18–24 months, and may continue filling out in chest and muscle mass until age 3.

A practical note on growth: giant-breed puppies should be fed a large-breed puppy formula that meets AAFCO guidelines for large-breed growth (calcium restricted to approximately 1.2% on a dry matter basis). Rapid growth from calorie-dense food increases the risk of developmental orthopedic diseases like hypertrophic osteodystrophy (HOD) and osteochondritis dissecans (OCD). Keep your Daniff puppy lean — you should be able to feel ribs easily without pressing hard.

Coat, Shedding, and Grooming Reality

The good news: regardless of which parent's coat a Daniff inherits, grooming is straightforward. Both the English Mastiff and the Great Dane have short, low-maintenance coats, so a Daniff will never need professional haircuts.

The coat will be short (0.5–1 inch), smooth, and lie close to the body. Most Daniffs inherit the Mastiff's double coat, which means moderate to heavy seasonal shedding — expect a noticeable coat blow in spring and fall. Some individuals may inherit the Great Dane's single coat, which sheds more consistently year-round but in lighter volume.

Is the Daniff hypoallergenic or low-shedding? No. This mix is not suitable for allergy sufferers. Both parent breeds produce typical levels of dander and shed regularly. If low-shedding is a priority, this is not the mix for you.

Grooming routine:

• Brush 2–3 times per week with a rubber curry brush or bristle brush (the Kong ZoomGroom works well on short-coated giants)
• Bathe every 6–8 weeks or as needed — over-bathing strips natural oils
• Clean facial wrinkles daily if Mastiff-type wrinkling is inherited (use a damp cloth, then dry thoroughly to prevent yeast infection)
• Trim nails every 2–3 weeks — giant dogs that walk on soft surfaces don't wear nails down naturally
• Brush teeth 3+ times per week; giant breeds are prone to periodontal disease

One grooming reality many owners underestimate: drool. If a Daniff inherits the Mastiff's loose lip structure (flews), you'll be wiping drool off walls, furniture, and your own clothing daily. Keep drool rags in every room. Great Dane lips are tighter, so Dane-leaning Daniffs may drool minimally.

Temperament: Best-Case and Challenging Scenarios

Temperament in a mixed breed is never guaranteed, but understanding the parental tendencies helps set expectations.

Best-Case Scenario

The Daniff inherits the Great Dane's friendly, eager-to-please nature combined with the Mastiff's calm, steady demeanor. The result is a confident, gentle giant that is good with children, tolerant of household chaos, and protective without being aggressive. This dog greets guests warmly but positions itself between its family and perceived threats. It's moderately active — happy with a 45-minute walk and some yard time — and settles into a couch companion by evening.

Challenging Scenario

The Daniff inherits the Mastiff's stubbornness and wariness of strangers without the Great Dane's social ease. The result can be a 180-pound dog that is difficult to leash-walk, resists training commands, and shows territorial guarding behavior that is hard to manage at that size. Same-sex aggression (particularly male-to-male) can occur, inherited from either parent line. Without early socialization, a Daniff with this temperament profile can become unmanageable.

Regardless of where a Daniff falls on this spectrum, early socialization is non-negotiable. A poorly socialized 200-pound dog is a liability risk that most trainers will not accept into group classes. Begin socialization at 8–10 weeks (after initial vaccinations) and continue structured exposure through at least 16 months. Use only positive reinforcement methods — force-free training with food rewards and praise. Given the dog's size, leash manners and a solid recall should be top priorities.

Health Considerations: Hybrid Vigor vs. Giant-Breed Reality

Let's address a persistent myth: hybrid vigor does not eliminate health problems in designer mixes. While crossbreeding can reduce the risk of breed-specific recessive conditions (like those caused by narrow gene pools), it does not protect against conditions that both parent breeds share. And in the case of the English Mastiff and Great Dane mix, both parents share several serious health risks.

According to the Merck Veterinary Manual, giant breeds face a distinct set of orthopedic and cardiac challenges simply due to their size. A Daniff inherits risk from both sides.

Health Conditions to Screen For

Health Risks in the English Mastiff and Great Dane Mix

Condition	Prevalence in Parent Breeds	What It Is	Screening Method
Hip Dysplasia	Both breeds: 15–25% affected (OFA data)	Malformation of the hip joint causing arthritis	OFA/PennHIP radiographic evaluation of both parents
Elbow Dysplasia	Mastiff: ~15%; Dane: ~10%	Abnormal elbow joint development	OFA elbow radiographs
Dilated Cardiomyopathy (DCM)	Great Dane: ~15% lifetime risk; Mastiff: elevated	Heart muscle weakens, leading to heart failure	Cardiologist evaluation + echocardiogram of parents
Gastric Dilatation-Volvulus (Bloat)	Great Dane: highest breed risk (~40% lifetime); Mastiff: high risk	Stomach fills with gas and twists — fatal without emergency surgery	No genetic test; preventive gastropexy may be recommended
Osteosarcoma	Both breeds: elevated risk vs. general population	Aggressive bone cancer, most common in limbs	No screening test; monitor for lameness or swelling
Hypothyroidism	Mastiff: moderately prevalent	Underactive thyroid causing weight gain, lethargy, coat issues	Thyroid panel (OFA thyroid registry)
Wobbler Syndrome (Cervical Spondylomyelopathy)	Great Dane: predisposed	Spinal cord compression in the neck causing gait abnormalities	MRI or CT if symptoms appear

Recommended Health Testing for Daniff Breeders

Any breeder producing English Mastiff and Great Dane mixes should provide documentation of the following for both parent dogs:

• OFA or PennHIP hip certification (good/excellent rating preferred)
• OFA elbow certification
• Cardiac evaluation by a board-certified veterinary cardiologist
• OFA thyroid panel
• Eye examination by a veterinary ophthalmologist (CERF/OFA eye registry)

If a breeder cannot or will not provide these results, walk away. Giant breeds are expensive to treat — a hip replacement (total hip replacement, THR) costs $5,000–$8,000 per hip, and DCM management can cost $200–$500 per month in medications for the dog's remaining life.

Always consult your veterinarian about breed-appropriate health screenings and preventive care for your individual dog.

Who Should (and Shouldn't) Own a Daniff?

The English Mastiff and Great Dane mix is not a dog for everyone. Here's an honest look at who thrives with this mix and who should consider a different breed.

This Mix Suits You If:

• You've owned giant breeds before and understand their specific needs (joint care, bloat prevention, short lifespan)
• You have a home with ground-floor access or no stairs — giant dogs with joint issues cannot navigate stairs safely
• You have a fenced yard (minimum 6 feet; Daniffs can be surprisingly agile) and space for a XXL crate (48–54 inches)
• Your household income supports $3,500–$6,000+ in annual care costs (food, joint supplements, veterinary care, pet insurance)
• You have time for daily training sessions and structured socialization during the first 18 months
• You're prepared for a 7–10 year commitment and the emotional weight of giant-breed end-of-life care

This Mix Is Not Ideal If:

• This would be your first dog — the training demands and physical management of a 150+ lb dog are overwhelming for new owners
• You live in an apartment or rental with breed/size restrictions
• You have very young children — not because Daniffs are aggressive, but because a 180-lb dog can accidentally injure a toddler simply by turning around
• You travel frequently and need boarding — many facilities have weight limits or surcharges for giant breeds
• You're on a tight budget — emergency surgery for bloat alone can cost $3,000–$7,000

Cost: Purchase Price, Annual Care, and Lifetime Budget

Owning an English Mastiff and Great Dane mix is a significant financial commitment. Here's a realistic breakdown based on 2025–2026 pricing.

Daniff Cost Breakdown

Expense Category	Cost Range
Puppy purchase (from health-tested breeder)	$1,500–$3,500
Adoption/rescue (if available — rare)	$200–$600
Initial supplies (XXL crate, bed, bowls, harness, leash)	$400–$800
Annual food (large-breed formula, ~15–20 lb/month)	$1,200–$2,400/year
Annual veterinary care (exams, vaccines, heartworm, flea/tick)	$800–$1,500/year
Pet insurance (giant breed, comprehensive)	$80–$150/month
Joint supplements (glucosamine/chondroitin, fish oil)	$300–$600/year
Emergency fund recommendation	$5,000–$10,000 set aside
Estimated first-year total	$5,500–$10,000+
Estimated lifetime cost (8-year lifespan)	$25,000–$50,000+

Breeder vs. Rescue: Daniffs are uncommon enough that dedicated rescue is rare. Check giant-breed rescues like Great Dane Rescue or Mastiff-specific organizations — mixed-breed giants do occasionally appear. When buying from a breeder, verify that both parents are on-site or that you can meet at least the dam. Ask for the health testing documentation listed above. Avoid breeders who advertise "rare" color premiums (blue, merle, harlequin) without commensurate health testing — color should never cost more than health.

Frequently Asked Questions

What two breeds make up the Daniff?

The Daniff is a cross between the English Mastiff and the Great Dane. Both are AKC-recognized giant breeds with guarding heritage. The mix is typically an F1 (first-generation) cross, meaning one purebred parent of each breed.

How big will an English Mastiff and Great Dane mix get?

Adult Daniffs typically weigh between 115 and 230 lb (52–104 kg) and stand 28 to 33 inches (71–84 cm) at the shoulder. Males are larger. The exact size depends on which parent breed the individual favors, and size can vary significantly even among littermates.

What is the temperament of a Daniff like?

Temperament ranges from the Great Dane's friendly, outgoing personality to the Mastiff's calm, reserved watchfulness. Most Daniffs are gentle, loyal, and good with family members, including children. Early socialization is essential regardless of temperament leaning, because a poorly socialized giant dog is difficult to manage safely.

Is the Daniff hypoallergenic or low-shedding?

No. Both parent breeds have short coats that shed moderately to heavily. Daniffs are not suitable for people with dog allergies. Expect regular shedding year-round with heavier seasonal coat blows if the Mastiff's double coat is inherited.

What health issues might a Daniff inherit?

The most significant shared risks include hip dysplasia, elbow dysplasia, dilated cardiomyopathy (DCM), gastric dilatation-volvulus (bloat), osteosarcoma, and Wobbler syndrome. Both parent breeds have shortened lifespans of 6–10 years. Reputable breeders screen parent dogs for hip, elbow, cardiac, and thyroid conditions through OFA or equivalent registries.

How much does an English Mastiff and Great Dane mix cost?

Puppies from health-tested breeders typically cost $1,500 to $3,500. Annual care costs (food, veterinary, supplements, insurance) range from $3,500 to $6,000+ per year. Lifetime ownership costs over an 8-year lifespan can reach $25,000 to $50,000 or more, particularly if major health issues arise. Rescue adoption, when available, costs $200–$600 but is uncommon for this specific mix.

Are Daniffs good with other dogs?

It depends on the individual and socialization history. Great Dane–leaning Daniffs tend to be more socially adaptable, while Mastiff-leaning dogs may show same-sex aggression or territorial behavior. Introduce new dogs carefully and always supervise interactions — at this size, even playful behavior can injure a smaller dog.

The English Mastiff and Great Dane mix is a magnificent animal, but it's not a casual choice. If you have the space, budget, experience, and commitment to raise a giant dog responsibly, a Daniff can be an extraordinarily rewarding companion — a gentle, loyal presence that fills a room and a home in every sense. If any of those requirements give you pause, consider a smaller breed or a well-socialized adult Dane or Mastiff from a breed rescue, where temperament and health history are already known.