50 lbs (23 kg) for a 17 month old GSD IS very small indeed.
The smallest male German Shepherd I have ever known was 32 kg at about 18 months old.
Your dog will actually fill out more and won't be fully mature until he is 2 and a half to 3 years old and he could put on some more weight but a long way to go to reach even 32 kg.
Your dog does not "look" like a mix and I assume he has been fed on quality food since puppyhood.
You may just have to accept he will be a small dog though. Why? Bad breeding or a genetic fault, its hard to say for sure without seeing the dog in the flesh and knowing his breeding lines.
He does not look like he suffers from Dwarfism, but it's a possibility. Google "Pituitary Dwarfism in the German Shepherd" for more info on this condition.
50 lbs (23 kg) for a 17 month old GSD IS very small indeed.
The smallest male German Shepherd I have ever known was 32 kg at about 18 months old.
Your dog will actually fill out more and won't be fully mature until he is 2 and a half to 3 years old and he could put on some more weight but a long way to go to reach even 32 kg.
Your dog does not "look" like a mix and I assume he has been fed on quality food since puppyhood.
You may just have to accept he will be a small dog though. Why? Bad breeding or a genetic fault, its hard to say for sure without seeing the dog in the flesh and knowing his breeding lines.
He does not look like he suffers from Dwarfism, but it's a possibility. Google "Pituitary Dwarfism in the German Shepherd" for more info on this condition.