What is the biggest dog in the world?
The answer depends on what you mean by “biggest.” A dog can hold a record for height, body weight or total length, and those records do not necessarily belong to the same animal.
By officially verified shoulder height, the tallest dog ever recorded was Zeus, a Great Dane from Michigan, who stood 111.8 centimeters (44 inches) tall at the withers.
Among living dogs, Guinness World Records currently lists another Great Dane, Reginald “Reggie” Johnson Reiss, as the tallest living male at 100.7 centimeters (3 feet 3 inches).
Biggest Dogs at a Glance
| Record | Dog | Measurement |
|---|---|---|
| Tallest dog ever | Zeus, Great Dane | 111.8 cm (44 in) at shoulder |
| Tallest living male | Reggie, Great Dane | 100.7 cm (39.6 in) |
| Tallest living female | Minnie, Great Dane | 97.5 cm (38.4 in) |
| Tallest female ever | Morgan, Great Dane | 98.15 cm (38.6 in) |
| Longest dog ever | Zorba, English Mastiff | 2.554 m (8.38 ft) |
| Zorba's verified weight | English Mastiff | 144.66 kg (319 lb) |
Dog records change over time. Measurements above reflect Guinness World Records information available at the time this article was updated.
What Was the Biggest Dog Ever?
If “biggest” means officially verified height, the answer is Zeus.
Zeus was a Great Dane owned by the Doorlag family in Otsego, Michigan.
Guinness World Records measured him on October 4, 2011.
His height from the floor to the withers—the highest point of the shoulders—was:
111.8 cm;
44 inches;
or 3 feet 8 inches.
When Zeus stood on his hind legs, he reached approximately 7 feet 4 inches tall.
He weighed about 70.3 kilograms (155 pounds).
Zeus died in 2014, but his verified height record has remained unbeaten.
Who Is the Tallest Dog Alive?
According to Guinness World Records' currently published male record, the tallest living male dog is Reginald “Reggie” Johnson Reiss.
Reggie is a purebred Great Dane living in Idaho Falls, Idaho.
He was measured at:
100.7 centimeters (1.007 meters / about 3 feet 3 inches) at the shoulder.
The measurement was officially recorded on January 27, 2025.
Reggie was born in September 2017, making him a mature adult rather than an unusually tall puppy that might continue growing.
Who Is the Tallest Female Dog Alive?
The tallest living female dog currently listed by Guinness is another Great Dane: Minnie Nogacek of Connecticut.
Minnie measured 97.5 centimeters (3 feet 2 inches) at the withers on June 7, 2025.
That puts her only a few centimeters below Reggie.
The tallest female dog ever recorded was also a Great Dane.
Morgan, from Canada, measured 98.15 centimeters in 2013.
This repeated appearance of Great Danes in height records is not accidental. The breed combines extremely long limbs with a tall, athletic body structure.
What Was the Heaviest Dog Ever?
Weight records are more complicated than height records.
One of the most famous giant dogs ever documented by Guinness was an English Mastiff named Aicama Zorba of La-Susa, usually known simply as Zorba.
Guinness records list several remarkable measurements:
length: 2.554 meters (8.38 feet);
shoulder height: 88.7 centimeters (35 inches);
chest girth: 1.447 meters (57 inches);
verified weight: 144.66 kilograms (319 pounds).
Zorba later reached approximately 153.5 kilograms (338 pounds) after being overfed while staying with a relative.
That higher figure should not be treated as an ideal target for giant dogs.
Extreme excess weight increases stress on joints, the cardiovascular system and other organs. A record-sized dog should not be made heavier simply to produce a larger number.
Why Isn't the Heaviest Dog Also the Tallest?
Height and weight describe different body shapes.
A Great Dane is built relatively tall and athletic, with:
very long legs;
a deep chest;
and a comparatively streamlined body.
An English Mastiff is built much more heavily, with:
massive bone;
a broad chest;
a huge head;
and substantially more body mass.
A Mastiff can therefore weigh far more than a Great Dane while standing lower at the shoulder.
What Is the Tallest Dog Breed?
Individual height records are dominated by Great Danes, but the Irish Wolfhound is generally recognized as the tallest dog breed overall.
Adult males commonly stand around 32 inches or more at the shoulder, and many reach approximately 34 to 35 inches.
Great Danes are also exceptionally tall.
The American Kennel Club standard gives adult male Great Danes a typical height of around 30 to 32 inches, although exceptional individuals can grow far beyond the normal breed range.
What Is the Heaviest Dog Breed?
The English Mastiff is among the heaviest recognized dog breeds.
AKC lists typical adult male Mastiffs at approximately 160 to 230 pounds.
That is considerably heavier than the normal male Great Dane range of approximately 140 to 175 pounds.
Saint Bernards, Newfoundlands, Leonbergers and several livestock guardian breeds can also reach extraordinary weights.
Great Dane vs. Mastiff vs. Irish Wolfhound
| Feature | Great Dane | English Mastiff | Irish Wolfhound |
|---|---|---|---|
| Main size trait | Extreme height | Extreme body mass | Very tall breed average |
| Typical male height | 30–32 in | 30 in and up | Often 32–35 in |
| Typical male weight | 140–175 lb | 160–230 lb | Often around 140–180 lb |
| Record connection | Tallest dogs ever | Extreme historical weights | Tallest breed overall |
Why Are Great Danes So Tall?
Great Danes were historically developed as powerful hunting dogs capable of pursuing wild boar.
Selective breeding produced a combination of:
long limbs;
substantial height;
powerful musculature;
and enough athleticism to move quickly despite large size.
The tallest record-holding Great Danes are extreme individuals even within an already giant breed.
A normal Great Dane should therefore not be expected to reach Zeus's height.
How Is the Tallest Dog Measured?
Official dog height is measured at the withers.
The withers are located at the top of the shoulder blades.
This is more reliable than measuring to the dog's head because a dog can raise, lower or tilt its head.
For a valid comparison:
the dog should stand naturally on all four feet;
the surface should be level;
and measurement should run vertically from the ground to the withers.
This explains why claims such as “my dog is six feet tall when standing up” cannot be directly compared with official canine height records.
Is a Dog Taller Than a Human?
At the shoulder, even the record holder Zeus was shorter than an average adult human.
But when he stood upright on his hind legs, Zeus reached approximately 7 feet 4 inches.
That made him taller than most humans.
This measurement is impressive but is not the measurement used for the official tallest-dog record.
Does Being Bigger Make a Dog Stronger?
Not automatically.
Size, pulling power, muscular strength, speed and bite mechanics are different traits.
A heavier Mastiff may have more total mass, while a lighter working breed may have better endurance or athletic performance.
For that reason, giant-dog records should not be used as a ranking of canine strength.
See our guide to the strongest dog breeds for a separate look at canine power.
Are Giant Dogs Healthy?
Many giant dogs can live happy lives, but extreme size comes with additional health considerations.
Large and giant breeds may be more vulnerable to problems involving:
joints and skeletal development;
heart disease;
gastric dilatation-volvulus, often called bloat;
and shorter average lifespans than many smaller breeds.
Growing puppies also require carefully managed nutrition so that growth is steady rather than excessively rapid.
Breeding or feeding dogs specifically to maximize record-breaking size is therefore not a responsible health goal.
FAQ
What is the biggest dog in the world?
If biggest means officially verified height, the tallest dog ever was Zeus, a Great Dane that measured 111.8 centimeters or 44 inches at the shoulder.
Who is the tallest dog alive?
Guinness World Records currently lists Great Dane Reginald “Reggie” Johnson Reiss as the tallest living male, measuring 100.7 centimeters at the shoulder.
What is the tallest female dog alive?
Minnie Nogacek, a Great Dane from Connecticut, holds the published Guinness record at 97.5 centimeters.
How tall was Zeus the Great Dane?
The all-time record holder Zeus measured 111.8 centimeters (44 inches or 3 feet 8 inches) from the ground to the withers.
How tall was Zeus standing on two legs?
He reached approximately 7 feet 4 inches when standing upright on his hind legs.
What was the heaviest giant dog ever recorded?
English Mastiff Zorba is one of the most famous verified giant dogs. Guinness records list him at 144.66 kilograms (319 pounds) during official measurement.
Was Zorba really 343 pounds?
Guinness records state that Zorba later reached about 338 pounds after being overfed. His officially documented measurement was 319 pounds, and the heavier figure should not be treated as a healthy target.
What is the tallest dog breed?
The Irish Wolfhound is generally recognized as the tallest dog breed overall, while Great Danes have repeatedly produced individual world height record holders.
What is the heaviest dog breed?
The English Mastiff is among the heaviest breeds, with adult males commonly weighing approximately 160 to 230 pounds.
Are Great Danes bigger than Mastiffs?
Great Danes are generally taller and more athletic in build, while English Mastiffs are usually heavier and broader.
Final Answer
The title “biggest dog in the world” depends on which measurement you use.
For height, the undisputed all-time Guinness record belongs to Zeus the Great Dane, who stood 111.8 centimeters (44 inches) at the shoulder.
The currently published tallest living male record belongs to another Great Dane, Reggie, at 100.7 centimeters, while Minnie holds the living female record at 97.5 centimeters.
For extreme body mass and length, English Mastiff Zorba remains one of the most remarkable documented dogs, with a verified weight of 144.66 kilograms and a length of 2.554 meters.
And when comparing breeds rather than individual record holders, the picture changes again: Irish Wolfhounds are famous for breed-wide height, Great Danes dominate individual height records, and Mastiffs dominate body mass.
So there is no single form of “biggest dog”—a dog can be the tallest, heaviest or longest, and each record tells a different story.
Related Reading
Sources Used for Fact Checking
Guinness World Records — Tallest Dog Ever
Guinness World Records — Tallest Dog Living (Male)
Guinness World Records — Tallest Dog Living (Female)
Guinness World Records — Tallest Dog Ever (Female)
Guinness World Records — Longest Dog Ever / Zorba
American Kennel Club — Great Dane
American Kennel Club — Mastiff
American Kennel Club — Irish Wolfhound
