i got my dog from a shelter at 6 months and they had to neuter him before he came home and i was wondering if neutering him could slow or affect his muscle growth or in any way slow maturity?
is there such thing as neutering to soon?
That's too young, IMO. As performanceknls said, they really need those hormones to grow. The way shelters look at it isn't in concern for the dog's health, but in preventing more dogs from going there in the future. If you look at the statistics, it's usually mixed dogs or low quality pure dogs that find their way to shelters...a good breeder finds buyers for the pups before they are born, and doesn't pop an add in paper when pups are 6 weeks old. The buyers of these pups are spur of the moment buyers who jump on it and often don't count the cost. They "dump" 'em off when they can't pay the piper. That's most likely what happened with your dog, and the shelter made sure no more will come.
As for S/N dogs, old timers I've spoke to have told me it takes an edge away from them. In simple English, they say it makes 'em curs (quitters.) They lose motivation sooner than if they were not fixed. However, I've seen fixed dogs that maintain the same intensity to get at others as when they were not S/N. But old timers speak from experience, so I tend to see a point and reason behind the things they say, JMO.
But, IMO, it's too late to worry about it now. What's done is done. Now you have these things to think about for the future, if you decide to get a pup from a breeder, rather than a shelter(where they fix 'em.)