Corgis are a long backed dwarf breed so they are at risk both back and hip problems if not managed correctly.  This starts in puppyhood with age appropriate exercises to ensure that their bones, muscles, ligaments and tendons all form properly. 

Puppies are much like human toddlers and children in the sense that their body is growing rapidly including bones, muscles, ligaments and tendons.  Care should be taken with puppies to prevent injuries as they grow. 

Puppies, like humans have “growth plates” at the end of their long bones.  These growth plates are where bone growth occurs allowing bones to lengthen as the puppy grows.  These growth plates stay open until the puppy is fully grown. How long these growth plates stay open depends upon the size and breed of the dog.  In Corgis, most of the time, growth plates close around 1 year of age.  Bones in Corgis grow most rapidly between 4 and 7 months of age.   

An injury during to a growth plate before it has closed can cause the plate to close prematurely thus preventing the bone to continue to grow.  When this happens, the dog may have a misshapen or shortened limb. 

Fractures

Puppies like humans do not reach their maximum bone density until after puberty.  This means that it is easy for puppies to fracture bones during periods of vigorous play or by jumping off of objects such as beds and couches.

Sprains and strains

Puppies can experience sprains and strains too.  Playing for excessive lengths of time, rapid twists and turns or jumping off objects can all cause problems. 

With this being said puppies must have exercise or their bones, muscles, ligaments and tendons will not properly form.