The moment a Great Dane puppy or a Mastiff pup crosses your threshold, the clock starts. Not because they're dangerous — they're not, by nature. But because a 100-pound dog has roughly six months before they're 150 pounds, and the behaviors that were manageable at 50 pounds aren't manageable at 150.
Training giant breeds isn't dramatically different from training other dogs. But the window for fixing problems is shorter, and the consequences of ignoring them are much heavier.
What "Giant Breed" Means
Giant breeds typically include Great Danes, Mastiffs (English, French, Bullmastiff), Newfoundlands, Saint Bernards, Irish Wolfhounds, Great Pyrenees, Leonbergers, Tibetan Mastiffs, Bernese Mountain Dogs, and similar large-framed dogs. Most reach 100+ pounds, some reaching 180+.
Key differences from medium and large breeds:
Growth plates close later: Giant breeds typically aren't skeletally mature until 18-24 months. Joint-stressing exercise (running, jumping, repetitive impacts) carries more injury risk during development than in smaller breeds.
Slower maturation overall: Mental and behavioral maturity also comes later. A two-year-old Great Dane is still adolescent in many ways. Patience is required for training timelines.
Sheer physical force: Even without jumping or pulling, a giant breed dog in motion is a force management issue. A dog that leans into greetings or puts their paws up on someone can knock down children, elderly people, or anyone unprepared.
Joint susceptibility: Hip dysplasia, elbow dysplasia, wobbler syndrome, and other orthopedic issues are elevated in giant breeds. This affects what physical exercise and sport is appropriate long-term.
What to Train First — And Why
Leash manners: Non-negotiable, earliest priority. A giant breed that pulls will injure someone — possibly you. Leash training guide covers the fundamentals. For giant breeds, start this at 10-12 weeks, before the dog has any pulling habit established.
Jumping up: A Great Dane that jumps at an adult is a manageable annoyance. A Great Dane that jumps at a child or an elderly person is a safety hazard. Stopping jumping up must be trained before the dog is physically capable of injuring someone. This is training through prevention, not correction — don't allow it, even when the dog is small and it seems cute.
Sit, down, stay: Basic position control at full size means the dog can be placed in a controlled position when situations require management. A dog that sits reliably when you ask is a dog you can manage in a waiting room, on a narrow sidewalk, or when other people approach.
Recall: For giant breeds, recall matters for both convenience and safety. A 150-pound dog off-leash without a reliable recall is a genuine risk in public spaces.
Physical Training Considerations
Avoid repetitive high-impact exercise until growth plates close. For giant breeds, that means:
- No sustained running on hard surfaces until 18-24 months
- No agility jumping or contact work until skeletal maturity
- Keep fetch sessions short — the stopping, turning, and jumping stress joints
- Swimming is generally safe for joint-related exercise because it's non-impact
After skeletal maturity, giant breeds can participate in most sports with appropriate warm-up and monitoring. They often do well in rally obedience, nose work, draft work, and water sports. Competitive jumping sports are higher risk given the orthopedic predispositions common to the group.
Temperament Notes
Most giant breeds were developed as companion or guardian dogs rather than working-line performance dogs. They tend toward:
- Calm, settled adult temperament when exercised appropriately
- Strong loyalty and bonding with family
- Variable sensitivity to strangers (mastiff types tend more guardian; Newfoundlands tend more social)
- Lower energy requirements than herding or sporting breeds
- Sensitivity to harsh training — giant breeds often respond to harsh corrections by shutting down
The gentle giant reputation is well-earned. They're often easy to live with as adults — but that adult temperament depends on the foundation built during the first two years.
The Cuteness Trap
Giant breed puppies are among the most appealing animals on the planet. An 18-pound Great Dane puppy with oversized paws and floppy ears will be allowed things that a medium-sized adult dog wouldn't be.
If you let the puppy jump on you because it's cute, you have six months before that habit is practiced into a 100-pound dog. If you let the puppy pull on the leash because you can manage it now, you have one year before you can't manage it anymore.
Stopping jumping up and consistent leash training, both started at eight weeks, are the most important investments you can make in a giant breed puppy. Start early. Stay consistent. The window is short and the payoff lasts a decade.