Heaviest Dog Breed Guide: 10 Giant Breeds Ranked by Size & Strength
Discover the heaviest dog breeds ranked by weight, strength, and temperament.
What Qualifies as the Heaviest Dog Breed?
The term "heaviest dog breed" refers to canines that consistently exceed 100 pounds (45 kg) in adult weight, with some individuals reaching 200+ pounds (90+ kg). These giants are classified by major kennel clubs as Working or Guardian breeds, developed historically for livestock protection, draft work, or estate guarding.
Selection Criteria for This List
- Minimum adult weight: 100+ lb (45+ kg) for males, 80+ lb (36+ kg) for females
- Breed recognition: AKC, UKC, or FCI registered breeds with established standards
- Consistent size: Breeds where the majority of individuals fall within giant weight ranges, not outliers
- Temperament data: Documented behavior profiles from breed clubs and veterinary behaviorists
- Health screening availability: Breeds with established OFA or PennHIP testing protocols
This list excludes mixed breeds, "designer" giants (like Daniffs), and breeds where extreme weight is considered a fault rather than standard. We've prioritized breeds you can actually find through responsible breeders or breed-specific rescues.
The 10 Heaviest Dog Breeds Ranked
1. English Mastiff
Size Class: Super Giant | Weight: 160-230 lb (73-104 kg) males, 120-170 lb (54-77 kg) females
Key Trait: Heaviest overall mass with the broadest chest circumference of any breed
The English Mastiff holds the record for heaviest dog ever recorded—Zorba weighed 343 lb (156 kg). Modern Mastiffs are calmer and more manageable but still require experienced handlers who understand giant-breed nutrition and joint care. Their gentle temperament makes them surprisingly good family dogs despite their intimidating size.
2. Saint Bernard
Size Class: Super Giant | Weight: 140-180 lb (64-82 kg) males, 120-140 lb (54-64 kg) females
Key Trait: Exceptional cold-weather endurance combined with massive bone structure
Originally bred for Alpine rescue work, Saint Bernards combine raw power with a gentle, patient nature. Their thick double coat and substantial body mass make them heat-intolerant—they thrive in cooler climates. Modern lines are slightly smaller than historic working dogs but still rank among the heaviest breeds.
3. Boerboel
Size Class: Giant | Weight: 150-200 lb (68-91 kg) males, 110-150 lb (50-68 kg) females
Key Trait: Highest muscle density and athletic power-to-weight ratio
This South African mastiff was developed to protect homesteads from predators including lions. Boerboels are more athletic and agile than typical mastiffs, with a confident, territorial nature that requires early socialization and consistent positive reinforcement training. Not recommended for first-time giant-breed owners.
4. Tibetan Mastiff
Size Class: Giant | Weight: 90-150 lb (41-68 kg) males, 70-120 lb (32-54 kg) females
Key Trait: Heaviest coat mass and most independent guardian temperament
Tibetan Mastiffs were bred to guard monasteries and livestock in the Himalayas. Their massive double coat adds significant visual bulk beyond their actual skeletal frame. They're notoriously independent and may not respond to traditional obedience training—early socialization is critical. Nighttime barking and territorial behavior are common without proper management.
5. Great Dane
Size Class: Giant (Tall) | Weight: 140-175 lb (64-79 kg) males, 110-140 lb (50-64 kg) females
Key Trait: Tallest breed with substantial weight despite leaner build
Great Danes are often called "Apollo of dogs" for their regal bearing. While not as massively built as mastiffs, their height (30+ inches at shoulder) combined with solid bone structure places them firmly in the heavy category. Their friendly, people-oriented nature makes them one of the most approachable giant breeds, though their size alone requires space and resources.
6. Newfoundland
Size Class: Giant | Weight: 130-150 lb (59-68 kg) males, 100-120 lb (45-54 kg) females
Key Trait: Heaviest water-resistant coat and strongest swimming ability
Newfoundlands were bred for water rescue and draft work in maritime Canada. Their webbed feet, water-resistant double coat, and natural swimming instinct make them unique among giant breeds. They're exceptionally gentle with children and other animals, earning the nickname "nanny dog." Drool and shedding are significant considerations.
7. Leonberger
Size Class: Giant | Weight: 110-170 lb (50-77 kg) males, 90-140 lb (41-64 kg) females
Key Trait: Most balanced giant breed with moderate energy and trainability
Developed in Germany as a versatile farm and family dog, Leonbergers combine substantial size with a more moderate temperament than many guardian breeds. They're highly trainable, enjoy water activities, and typically get along well with other pets. Their lion-like mane and balanced proportions make them visually striking without the extreme mass of mastiffs.
8. Anatolian Shepherd
Size Class: Giant | Weight: 110-150 lb (50-68 kg) males, 80-120 lb (36-54 kg) females
Key Trait: Highest endurance and lowest maintenance coat among giants
Anatolian Shepherds are Turkish livestock guardians bred for independence and stamina. They're more aloof and territorial than family-oriented breeds, making them better suited to rural properties than suburban homes. Their short coat requires minimal grooming, but their protective instincts demand experienced handling and secure fencing.
9. Neapolitan Mastiff
Size Class: Giant | Weight: 150 lb (68 kg) average, up to 200 lb (91 kg)
Key Trait: Most distinctive appearance with extensive loose skin and wrinkles
Neapolitan Mastiffs are ancient Italian guardians recognizable by their massive heads, loose skin, and solemn expression. They're typically calm and quiet indoors but require early, extensive socialization to prevent over-protectiveness. Wrinkle care and drool management are daily requirements. Not ideal for fastidious housekeepers.
10. Irish Wolfhound
Size Class: Giant (Tall) | Weight: 120 lb (54 kg) minimum, typically 120-180 lb (54-82 kg)
Key Trait: Tallest sighthound with surprising weight despite lean build
Irish Wolfhounds are the tallest of all dog breeds, with males standing 32+ inches at the shoulder. Their deep chest and long legs contribute substantial weight despite a more athletic build than mastiffs. They're gentle, dignified, and surprisingly good with children, though their size and relatively short lifespan (6-8 years) require emotional and financial preparation.
Comparing the Heaviest Breeds: Key Attributes
| Breed | Avg Weight (M/F) | Height | Energy Level | Trainability | Family Fit |
|---|---|---|---|---|---|
| English Mastiff | 160-230 / 120-170 lb | 30+ in | Low | Moderate | Excellent |
| Saint Bernard | 140-180 / 120-140 lb | 28-30 in | Low-Moderate | Moderate | Excellent |
| Boerboel | 150-200 / 110-150 lb | 24-28 in | Moderate-High | High | Moderate |
| Tibetan Mastiff | 90-150 / 70-120 lb | 26-30 in | Low | Low-Moderate | Moderate |
| Great Dane | 140-175 / 110-140 lb | 30-34 in | Moderate | High | Excellent |
| Newfoundland | 130-150 / 100-120 lb | 28-30 in | Moderate | High | Excellent |
| Leonberger | 110-170 / 90-140 lb | 28-31 in | Moderate | High | Excellent |
| Anatolian Shepherd | 110-150 / 80-120 lb | 29-32 in | Moderate | Low-Moderate | Low-Moderate |
| Neapolitan Mastiff | 150-200 lb | 26-31 in | Low | Moderate | Moderate |
| Irish Wolfhound | 120-180 lb | 32-35 in | Moderate | High | Excellent |
Why These Breeds Made the List
Each breed was selected based on documented weight ranges from AKC breed standards, veterinary body condition data, and real-world measurements from breed clubs. We prioritized breeds where giant size is a consistent trait, not just occasional outliers.
English Mastiff: Consistently the heaviest breed by total mass, with documented individuals exceeding 300 lb. Their broad chest and substantial bone structure create unmatched overall bulk.
Saint Bernard: Historic working lines were even larger than modern show dogs, but current standards still produce dogs in the 140-180 lb range with exceptional cold-weather endurance.
Boerboel: Higher muscle density than typical mastiffs, with athletic power that makes them feel heavier than their weight suggests. Their working heritage demands functional strength.
Tibetan Mastiff: Their massive coat adds visual bulk, but skeletal measurements confirm substantial frame size. Males routinely exceed 120 lb with some lines reaching 150+ lb.
Great Dane: While leaner than mastiffs, their exceptional height (30-34 inches) combined with solid bone structure results in weights comparable to bulkier breeds.
Newfoundland: Dense bone structure and heavy water-resistant coat contribute to their substantial weight. Working lines are often heavier than show lines.
Leonberger: Balanced proportions with substantial bone and muscle. Males can reach 170 lb while maintaining athletic movement.
Anatolian Shepherd: Lean but substantial, with endurance-focused build that still produces 110-150 lb adults. Their working heritage prioritizes function over extreme mass.
Neapolitan Mastiff: Extensive loose skin and heavy bone structure create impressive mass. Their ancient guardian lineage selected for intimidating size.
Irish Wolfhound: Despite their lean sighthound build, exceptional height and deep chest produce surprising weight. Males typically exceed 120 lb minimum standard.
Decision Framework: Choosing Your Giant Breed
If you want a calm family companion:
Choose: English Mastiff, Newfoundland, or Leonberger
Why: These breeds have the most documented gentle temperaments with children and other pets. They're typically lower energy indoors and respond well to positive reinforcement training.
If you need livestock or property protection:
Choose: Anatolian Shepherd, Tibetan Mastiff, or Boerboel
Why: These breeds retain strong guardian instincts and independence. They require experienced handlers, secure fencing, and early socialization to manage protective behaviors appropriately.
If you want an active giant for outdoor activities:
Choose: Leonberger, Newfoundland, or Irish Wolfhound
Why: These breeds have higher endurance and enjoy activities like hiking, swimming, or cart pulling. They're more athletic than typical mastiffs while still maintaining giant size.
If you're a first-time giant breed owner:
Choose: Great Dane, Leonberger, or Newfoundland
Why: These breeds are generally more forgiving of training mistakes and have extensive breed club support networks. They're easier to socialize and typically more eager to please than independent guardian breeds.
Honorable Mentions & Breeds to Consider Carefully
Honorable Mentions:
- Dogue de Bordeaux: Smaller overall (99-110 lb) but extremely stocky with substantial mass
- Bullmastiff: 100-130 lb with a more manageable size for smaller properties
- Cane Corso: 88-110 lb with athletic build; borderline for "heaviest" category but worth considering
Breeds to Approach with Caution:
- "Teacup" or "miniature" giants: Unethical breeders may market undersized versions of giant breeds—these often have severe health issues
- Mixed-breed "designer" giants: Daniffs (Dane-Mastiff crosses) and similar mixes lack predictable temperament and health screening
- Overweight individuals of smaller breeds: An obese Labrador is not a "giant breed"—focus on breed standards, not individual outliers
Costs & Considerations for Giant Breeds
Owning one of the heaviest dog breeds requires significant financial and logistical preparation:
- Initial purchase: $1,500-$4,000 from health-tested breeders; breed-specific rescues may have adults for $300-$800
- Annual food cost: $1,200-$2,400 for high-quality giant-breed formulas (look for AAFCO statements and controlled calcium/phosphorus ratios)
- Medical expenses: $800-$2,000 annually for joint supplements, cardiac screening, and giant-breed-specific health issues
- Equipment: $500-$1,500 for XL crates, raised feeders, heavy-duty leashes, and vehicle ramps
- Emergency fund: Minimum $5,000-$10,000 for potential bloat surgery, hip dysplasia treatment, or cardiac care
Giant breeds typically live 6-10 years, so budget planning should account for accelerated aging and earlier onset of age-related conditions. Consult your veterinarian about giant-breed-specific nutrition protocols, particularly controlled growth rates for puppies to reduce orthopedic disease risk.
Frequently Asked Questions
What is the heaviest dog breed in the world?
The English Mastiff is consistently the heaviest breed by total mass, with males averaging 160-230 lb (73-104 kg). The record holder, Zorba, weighed 343 lb (156 kg) in 1989.
Are giant breeds good with children?
Many giant breeds like Newfoundlands, Leonbergers, and English Mastiffs are excellent with children due to their gentle, patient nature. However, their size alone can accidentally knock over small children, so supervision is always necessary.
Do heavy dogs eat significantly more food?
Yes—giant breeds typically consume 6-12 cups of high-quality kibble daily, costing $100-$200 per month. Giant-breed puppy formulas are essential to control growth rates and reduce orthopedic disease risk.
What health problems are common in the heaviest breeds?
Common issues include hip and elbow dysplasia, gastric dilatation-volvulus (bloat), cardiac disease, and certain cancers. Regular veterinary screening and maintaining lean body condition are critical preventive measures.
Can giant breeds live in apartments?
Some lower-energy giants like English Mastiffs can adapt to apartment living if they receive adequate daily exercise. However, their size makes small spaces challenging, and most thrive in homes with more room to move comfortably.
How long do the heaviest dog breeds live?
Giant breeds typically live 6-10 years, with some variation by breed. Irish Wolfhounds average 6-8 years, while Leonbergers and Newfoundlands may reach 8-10 years with excellent care and genetics.
For more information on giant breed care, consult the Merck Veterinary Manual or connect with breed-specific clubs through the AKC breed directory. Always work with veterinarians experienced in giant-breed medicine for optimal health outcomes.
Jonas Cole
All our authors care for dogs every day — read more of their work on the authors page.
