But exercise that’s not appropriate for a puppy’s age and development can cause significant and irreversible damage. What would be a simple sprain in an adult dog could leave a puppy with a misshapen or shortened limb, so this is a subject that should be taken seriously.

The first consideration with puppy exercise is something called “growth plates.” Growth plates are soft areas that sit at the ends of the long bones in puppies and young dogs. They contain rapidly dividing cells that allow bones to become longer until the end of puberty. Growth plates gradually thin as hormonal changes approaching puberty signal the growth plates to close. In puppies, this closure is normally completed by approximately 18 months old.

This kind of juvenile injury is known as “Toddler Fracture” in humans, and it’s thought to be caused by the fact that the outside, fibrous layer of the bone (periosteum) is relatively strong in relation to the elastic bone inside. So any exercise that puts torque on (twists) a bone puts the puppy at risk for a fracture.

After reading about growth plates and toddler fractures, you may find yourself clutching your puppy, afraid to let him move lest he breaks a limb. Relax! Not only is appropriate exercise not dangerous for your puppy, exercise has been shown to increase bone density in children.

Furthermore, those children who exercised were a whopping 50% less likely to fracture a bone. There’s every reason to believe the same holds true for dogs, so appropriate exercise is key to building strong bones in your puppy and preventing adult fractures. So let’s talk about guidelines for puppy exercise.

A study of 500 Newfoundland, Labrador, and Leonberger puppies found that puppies who climbed flights of stairs daily before they were 3 months of age had an increased risk of developing hip dysplasia. Although these breeds were selected for the study because of their relatively high incidence of hip dysplasia, the study seems to indicate that stairs represent a strain on any puppy’s joints, so consider ramps or carrying your puppy down stairs if possible.

Interestingly, the same study found that off-leash self-directed exercise on gently rolling, varied, and moderately soft ground for puppies under 3 months old decreased the risk of developing hip dysplasia.

And it’s important to get that exercise in early-free play after 12 weeks old, while certainly beneficial in general, was not shown to decrease the risk of hip dysplasia in the study. So, once again, self-directed play in your backyard or garden is the best exercise for young puppies.

• These are guidelines based on our personal experience with broken toes, broken bones, soft tissue injuries, torn cruciate ligaments, and all other manner of exercise and play injuries in the 33 years that we’ve had Bull Terriers. You may find it too conservative or not conservative enough, but this is our best recommendation based on our experience and the available studies.
  
  
• I am not a veterinarian, and this is not intended as veterinary advice. You should always consult your breeder and veterinarian about the best exercise program for your puppy.
  
  
• These ages for growth plate closure are only generalities and will vary from puppy to puppy. There will also be a difference in recommendation based on your dog’s breed - giant breed puppies’ growth plates tend to close later and small breed puppies growth plates close earlier.
  
  
• Sex hormones are what signal growth plates to close, so If your puppy was neutered before around 18 months old, he will have some delay in growth plate closure, and he will also have uneven growth in his bones resulting in joint angles that could be more liable to injury. A more conservative approach may be warranted with early spay/neutered dogs.
  
  
• There are breed-specific orthopedic concerns which are not addressed here.
  
  
• For any dog that you wish to enroll in a strenuous performance career, we highly recommend doing x-rays to confirm growth plate closure before proceeding with any intense training.