My puppy Boris is a 6 month old Russian Black Terrier with only one descended testicle. We have been assuming that it is unlikely that the remaining testicle will descend now, and that we will have to have him castrated for health reasons (mainly the likelihood of cancer in undescended testicles).

We don't intend to breed Boris, mainly because of the risk that the undescended testicle is a genetic problem.

Boris is a dominant personality (dogality?) and we have had to take care to show him we're top dogs in this house. He is possessive over bones (not too bad...) but has recently started trying it on by growling when we remove him from some "treat" he shouldn't have - such as drinking the pond or going through the rubbish bin. We do all the usual stuff such as eating first, moving through doors first, not allowing him on settees etc. to achieve this, and generally I'm happy that we have this in control. Boris has shown no sexual instincts yet, totally ignoring a bitch on heat on a recent walk. He doesn't cock his leg yet, or show any mounting behaviours.

If Boris had been a normal male with two descended testicles, I would have been unsure about castration. The pros and cons for us seem to be

Pros
1) When we're abroad he will be able to stay in an excellent "kennel" in which up to 8 dogs share the proprietor's house (entire males not accepted). I would feel very unhappy leaving him locked up in a cage with just an occasional run. We go abroad 2-4 weeks a year.
2) Our friends tell us we'd be mad not to have the op, and assure us that entire males can be very dominant and difficult to manage.
3) It seems unfair to leave a dog with sexual instincts and no way of fulfilling them.

Cons
1) Boris's personality might change for the worse. Although he is a handful, I admire his brave and confident manner, and I do think that we know enough about dogs to ensure that he is not the top dog in this house... too often :-)
2) It seems wrong to do something like this to another living thing without his consent.
3) I'd prefer to avoid general anaesthetic where possible.

So my questions are

a) Is it absolutely necessary to remove the undescended testicle, medically speaking? Is there any chance the remaining one will descend naturally now?
b) Is vasectomy (of the remaining testicle) an option? (I don't know yet if the kennel would accept this, or only accepts castrated males...)
c) What age should castration and/or vasectomy be done?

Wait for another 6 months before you think about what to do. Ja:)kie

I tend to agree with Jackie, esp. waiting for the teste to drop.

Please remember that the personality the dog shows from birth to 5-8 months, and then from 5-8 months through adolescence isn't necessarily what he'll turn out at adulthood. The teenage 'years' are difficult and full of testing... similar to us humans. He will push boundaries and rules -- just take it in stride as part of growing up. Be firm and consistent in your reaction. :)

Have to admit, I did get a smile out of:
It seems wrong to do something like this to another living thing without his consent. Taking anthropromorphism a tad bit far imo ;) :D