2 young cats to home with 10 year old cat

Question
I have a 10 year old neutered/declawed himalayan who has had an attitude since day one.  

I have brought in two other himalayans, a male 5 years old and female 2 years old.  These two are not fixed nor declawed (and I think the female is pregnant).

Realistically I suspected that the males would have a problem with each other, although initially they were pretty cool, sleeping close together, eating together, etc.  

Now they have obviously want to prove rank and I am wondering whether my long time friend will ever give up hierarchy and make friends with the new male or maybe the new male will give up or am I to expect constant bickering?

Or is it that the female being supposedly pregnant the younger male is being protective?

Thank you.

Answer
Hi Erma, thank you for taking in some older, "not kittens" in your home!  How long have you had the two new ones in your home?

When I adopted/rescued 2 new cats for our home, a 9 year old and a 7 year old in March 06, we already had a fixed male 3 years old that is a cool and people loving cat - I researched this question... how long would it take for them all to get along - I read it would be approximately 6 months so I waited.  Realistically it took more than that - Almost 1 year before everyone here settled down into their new pecking order : - )  But everyone was fixed and front declawed so they had an even playing field.

Because your new male is not neutered, that is the main cause of the problems between your males.  The unfixed male can become more agressive with time, so the sooner he is fixed, the better for your household!  Also once the female is fixed, it will be easier for them to settle down.  It still may take about a year before everyone get's used to each other.

I believe your older friend will adjust fine after he has no competition from the un-neutered male.  The two cats you brought in later may develop a close relationship and bond, but will still accept your older buddy.

Thank you and good luck with all 3 of your wonderful companions.

Debbie