Kay,

Both of my "girls", Lilly and Honey, were done as soon as my vet said they could be, before they ever went into their first heat. It was 5 months old, for both of them.

I asked Mack's breeder about the best time to neuter him since we had absolutely no plans to use him as a stud, even though I'm certain he would have been a good one! We tried to wait until he was fully developed, one year old, but he did become aggressive, and he was neutered at 10 months old. You might remember that he got into it with a foster Golden Retriever, and he "lost" the fight, but we knew it was time. He did just fine. He has not settled down completely, yet, and we won't even attempt to foster for a while now, but had the breeder not said that we should wait until one year, we would have done it at six months.

I think with Moo being already six months old, you couldn't go wrong going ahead and neutering him, but it is your decision, with advise from your vet.

Good luck.
Logan