German Shepherds are a large-breed dog which generally are between 55 and 65 centimetres (22 and 26 in) at the withers and weigh between 22 and 40 kilograms (49 and 88 lb). The ideal height is 63 centimetres (25 in), according to Kennel Club standards.
German Shepherds are highly active dogs, and described in breed standards as self-assured. The breed is marked by a willingness to learn and an eagerness to have a purpose. Shepherds have a loyal nature and bond well with people they know. However, they can become over-protective of their family and territory, especially if not socialized correctly. An aloof personality makes them approachable, but not inclined to become immediate friends with strangers. German Shepherds are highly obedient and not easily distracted, but due to their strong self-will must be trained by "a firm hand"
Intelligence
German Shepherds were bred specifically for their intelligence, a trait for which they are now renowned. They are considered to be the third most intelligent breed of dog, behind Border Collies and Poodles. In the book The Intelligence of Dogs, author Stanley Coren ranked the breed third for intelligence. He found that they had the ability to learn simple tasks after only five repetitions and obeyed the first command given 95% of the time. Coupled with their strength, this trait makes the breed desirable as police, guard, and search and rescue dogs, as they are able to quickly learn various tasks and interpret instructions better than other large breeds.
Aggression
German Shepherds have a reputation for aggression and have been banned in some jurisdictions as a result. In the United States, German Shepherds are responsible for more random bitings than any other breed, and have a known tendency to attack smaller breeds of dogs. Reports have found that statistically German Shepherds are the breed third most likely to attack a person. Another report found that German Shepherds accounted for almost half of the dog bites that required medical attention. These claims have been refuted on the basis that German Shepherds represent a higher proportion of the population than other breeds. However, reports indicate that Shepherds are over-represented when the statistics take into account the difference in population
Many common ailments of the German Shepherds are a result of the inbreeding required early in the breed's creation. One such common issue is hip and elbow dysplasia which may lead to the dog experiencing pain in later life, and may cause arthritis. Due to the large and open nature of their ears, Shepherds are prone to ear infections. German Shepherds, like all large bodied dogs, are prone to bloat.
The average lifespan of a German Shepherd is 7 - 10 years, which is normal for a dog of their size. According to a study done by R.M. Clemmons, DVM PhD who is a Professor of Neurology and Neurosurgery at the University of Florida, Degenerative Myelopathy, or DM is a neurological disease that occurs with enough regularity specifically in the breed to suggest the disease is one that is genetically predisposed in German Shepherd Dogs. Additionally, German Shepherd Dogs have a higher than normal incidence of Von Willebrand Disease, a common inherited bleeding disorder.
