Canine Brittle Bone Disease (Osteogenesis Imperfecta) is a genetic mutation which occurs from the lack of an enzyme required for normal bone formation, impairing development of Collagen, resulting in bones being abnormally brittle and susceptible to fracture.
Although the bones are of normal length, they are weaker and thinner than usual, prone to multiple fractures. Dogs may be lame due to fractures or due to malformed bones resulting from healed fractures. Dogs can very easily break bones. Tendons may be abnormally weak.
In severely affected dogs even the act of breathing can result in broken ribs. Animals with this degree of severity usually do not survive. The condition may also affect the teeth, so that teeth can easily break off. However, in mild cases there may be no fractures at all.
In addition to brittle teeth and bone fractures, symptoms can also include loose joints, weak muscles and tendons, a curved spine, and even hearing loss. In severe cases an affected puppy would have to be euthanized.