German shepherd like any other dog are prone to genetically transferred health problems. If a breeder tells you that it is a strong breed that would eat anything, stay idle for a long time and would still be healthy, is a fraud.
German shepherd are vulnerable to hip dysplasia, but many breeders today are working on medications that would minimize this genetic diseases. A dog with hip dysplasia would find it difficult to sit and walk as the thigh bone remains detached to the hip socket. Over a period of time, the bone starts wearing and turns into painful arthritis. The early stages of hip dysplasia can be managed with affordable medications, whereas in severe cases a surgical replacement is required. A dog owner cannot tell by simply watching the dog whether the dog is suffering from hip dysplasia or not. It is only through regular vet visit and X-rays that you can indicate the problem.
Other diseases common in German shepherd includes vision problems, epilepsy, immune diseases, bleeding disorders, digestive problems, hemangiosarcoma, and pancreatic insufficiency- all such conditions are found to be common in German shepherd. If any of the parents of the dog have had similar issues- any breeder would immediately be able to foretell.
Just as diseases are genetic, the temperament of this dog is also heritable. Take your dog to a vet and start some temperament testing. An aggressive, unstable, and shy German shepherd would be hard to train and dangerous to keep. In America, many states have banned keeping this dog as a pet if they do not pass the TT (Temperament Test). But otherwise, they are caring and protective. They would listen to your commands and will be more obedient than a soldier.
With medium length but thick coat, you will find its fur to be constantly shedding. When the season changes, especially during fall and spring, it is important to bath and brush your dog frequently to get rid of the lose hair. Brushing for the rest of the week is only to keep them clean and healthy. It is recommended to not keep a German shepherd indoors if you have allergies or are sensitive to skin diseases.