best age to fix german shepard dog

Question
My german shepard dog is now 6 months I wonder what is the best age to get him fixed? I hear at 2 years because of their growth. They will be more muscular and stronger if I wait. He jumps up alot and I was told if I get him fixed now he will stop that. What do you think?

Answer
I think this is an area with many strong opinions with little to back them up.  My opinion?  Six months has long been the standard and there is very little evidence otherwise.  My advice? Talk to your vet and go with his recommendation. That is also what the AVMA says, http://www.avma.org/animal_health/brochures/spay_neuter/spay_neuter_brochure.asp

I have a degree in chemistry and have been trained to base my opinions of facts, not speculation.  I also have experience managing a factory, and fine theories with nothing to back them up are not help in keeping production going.  While the idea that delayjng neutering sounds good to some, there are no good studies to back it up.  At best, is may make a minor difference.