His father and mother were both oversized, if the numbers you state are correct. Your boy is within the doberman standard now. You shouldn’t expect a fully mature male dobe to be any more than 85-90 pounds. He sounds a good weight now for his age (and some male dobes will stay at that weight--that’s OK) but he should continue to add weight and muscle mass (but generally not height) until he is two or even three years old.
Can you see ALL of his ribs easily when he is just standing still? Do you see his backbone or hip bones sticking out? Those could be signs he needs more food for his activity level--but if he just looks like a teenager...well, that is what he is.
The key to exercise at this age is that you shouldn’t be asking him to do anything repetitively (like jogging or biking as an only form of exercise) and also you shouldn’t be asking for a lot of jumping or sudden turning and twisting (which fetch can be, if you’re not careful) He should be able to stop exercising when he wants to and smell the roses, so to speak (he will try to keep up with you if you are jogging or biking, for example, so you can push him too hard without realizing it). Some dogs will obsess on fetching too (my boy is obsessed with tennis balls) and can overdo it that way.
Don’t try to pack weight on him by overfeeding--that will just make for a fat dog with joint problems. He will grow to the size he is meant to, with good food and proper exercise. You should be able to see his last few ribs when he is standing still, and easily feel his other ribs, when he is at a proper weight.
he's full European dobie, 110 and 90 lbs for male and female European dobies is quite normal. His hipbones do stick out, quite a lot sometimes, and based on a lot of other factors i decided to feed him a cup more each day. Thanks for your help