What is the optimal age to neuter my Lab?

Question
QUESTION: I have an almost 12mth (2/3/10)old english lab that we got from a breeder.  She suggests we wait until he is 12-18mths to neuter him. (By contract we can't go any longer than 18mths).  She had stated if we wait, it is better for bone growth and hopefully he
will be less likely to have issues later on in life. From what I've read besides what I listed above, I've learned that he might be less likely to be bulky/muscular if we neuter him at 12mths vs 18mths.   My question is - does 12 mths to the 18mth mark, make that much of a difference?  Spring is around the corner and we thought maybe we should just get it over with before we start having issues(ie:more aggressive)- but if it's best for him to wait we will - what do you think?

ANSWER: I am not sure how much of a difference there is between 12-18 months.  Different lines mature at different rates, and waiting as close to the 18 months ensures that he's fully developed.  

Any "issues" are training issues.  As I show dogs, I have my males intact.  I only just recently neutered my old male (+8 years) due to testicular cancer.  But for the last few years, I have had 3 intact boys in the house and no "issues".  They don't mark in the house, they aren't aggressive with one another, they aren't aggressive with other dogs.  As long as the dog knows that you are in charge and respects that, you should have no aggression issues or any other stereotypical issues.  

Is your breeder close enough that you could visit with the boy and have her look at him?  If she thinks he's done growing, then you could do it at 12 months.  Typically size-wise they are done growing at about 12 months, but that last 6 month to even a year gives them time to develop their body a bit more.  Their rib cages become a bit wider, they just finish overall maturation.  My boys are nearing 2 and I am still seeing changes as they grow older.  

There are things that you can't do with an intact boy, such as most doggy day care facilities won't take them, it's harder to find a place to board them if you go away.  If you are having any issues like that, I don't see a reason to wait much past 12 months.  But if your life and schedule allow, I would do it as close to 18 months.  

You bought a nice dog from a good breeder with hopefully a nice pedigree so you might as well allow that last 6 months to let the dog become all it should be before he's neutered.

---------- FOLLOW-UP ----------

QUESTION: Thank you for responding!  I'm glad to know that if they aren't aggressive now they shouldn't become aggressive just because they are maturing.  But will I see more "excitement" or possible wanting to wander for a female because he's maturing?  He's mostly in the house with us, but I do walk him several times a day.  As you said about your boys - our dog does not mark in the house, but he does mount his bed sometimes, will this also become more prevalent?  Great idea about our breeder - but she is 9 hours away!  Our dog - Hudson, is 11 1/2 mths and he weighs approx 85lbs.  He is 25 inches at his withers.  His father is 110 and his mother is 90.  So I'm assuming he will be as big as them.  Can you tell by looking at a picture?(would you have any idea?)  If not - as you stated, we will see what happens in our lives, but hopefully be able to wait until the summer before we neuter him.  Again I appreciate your advice!

Answer
I found my oldest male was a bit hard for me to train off-leash, though he was much better with my husband.  But I never had him wander off in search of a female in heat.  We have an intact female at our home, and even during her seasons it's completely manageable.  Yes, the humping is MORE prevalent as well as crying and not leaving her alone.  But before we got her, we never had issues with him wandering off.  But then again, we also always supervised even in our fenced yard.  

With humping his dog bed, just tell him NO and redirect his attention with a fun toy or chew bone.  If you have to put the bed away until the fixation has gone away, you can do that too.  My old boy used to do that when he was young, and my young guys never did it at all.  It's sometimes more dominance related, as in when they are at the bottom of the pack, they will hump their bed in order to have dominance over something.  Or even if they get overly excited, sometimes it will manifest in humping.  Even females will hump.

At his age now, he's probably as big as he's going to be.  He might gain a bit more, but that all depends on his activity level.  My younger boys were pretty much done at about a year, though they've put on a bit more weight and broadened in the chest.  You can look at Hudson's front "wrists".  If they aren't knobby anymore, and most likely they aren't, he's done growing.  That's usually a sign that the growth plates have closed and the long bones in the legs won't be growing anymore.