Carry the seventy-pound puppy

A Great Dane puppy gains weight faster than the skeleton can finish setting. By six months your dog is the size of a fully grown Labrador. By twelve months they look like an adult to anyone who isn't paying attention. They are not an adult. The growth plates — the soft cartilage at the ends of long bones where new bone is still forming — don't fully close until somewhere around eighteen months. Some lines later.

Everything you do in those eighteen months is either putting deposits in the joint account or withdrawals. The math compounds.

The list of withdrawals

The high-cost activities, in roughly the order owners regret them:

• Stairs. Especially down. The eccentric load on the front shoulders and elbows is the worst case. If you live in a multi-story house, the puppy lives on one floor for now. Baby gate at the top. Carry up and down — yes, even at fifty pounds; yes, even at seventy.
• Jumping. Off the couch, out of the car, off the back deck. The impact is concentrated through joints that haven't finished. A ramp into the car solves this for a hundred dollars. Use one.
• Hardwood and tile. Polished floors are a slip waiting to happen. A dog that goes down hard on smooth flooring can tear ligaments that don't show up until they're chronic. Runners through the main paths. Toe-grips on the back feet if you can get them on.
• Forced exercise. A puppy following you on a five-mile run is not a happy puppy doing what they love. They will follow because that is what Danes do. Their joints will pay the bill quietly. Free play in a yard, on grass, where they choose the pace, is the right amount of motion. Structured leash walks come in slow.
• High-impact play with bigger dogs. A four-year-old Rottweiler bodychecking your nine-month-old Dane is exactly the kind of moment that registers later. Supervise. Interrupt before it gets rough.

The list of deposits

• Lean body weight. A pudgy puppy is the single largest joint risk you can manufacture. If you can't see a faint waist from above, the bowl is too full. Ask your vet to score body condition every visit and write it down.
• Slow, low-impact motion. Walking on grass. Swimming if you have water access — exceptional for Danes. Sniff walks where the goal is olfactory, not aerobic.
• A surface they don't slip on. Worth saying twice. Half of the joint trauma I hear about happened on a kitchen floor.
• Glucosamine, chondroitin, omega-3s. Foundational, not heroic. Start them young. Don't expect to feel the difference. Expect the absence of a problem at age six that you won't otherwise be able to attribute.
• A vet who knows giant breeds. Standard large-breed dosing and protocols undershoot here. The right vet will tell you.

What month 18 looks like

You ease the rules. Stairs become normal. The dog joins the longer walk. The leash relaxes. By two, your Dane is the adult their body was always going to be — and the joints under that body had time to finish becoming joints.

The eighteen months feel long when you're in them. They are the cheapest insurance the breed has.