I have a 5 year old spayed bitch and am considering getting a second dog.  I have been informed that it would be inadvisable to get a male with already having a bitch.  Is this true?

No, it's not true.  A male with a spayed bitch are the couplings most likely to get along IME (although the bitch is likely to rule the male!).  I have 2 male dogs who get on great and then introduced a much older bitch with no problems.  The only problems were with my parents' bitch and mine, but all those were sorted in a short time and all four dogs are now perfectly happy with each other.

I had a bitch first. Although she's so laid back I could of had either sex for a second dog.  I decided to get a dog puppy. As Benjidog says my bitch does rule the roost out of the two. She has put him in his place but absolutely adores him and they won't stop playing together.

what about 2 bitches is this a no i have a 5 year yorky bitch and want to buy a pup

I own five bitches with 2 to four year age gaps and all get along just fine, even when there was an aleration in the hierachy with the oldets stepping down to allow her grandaughter (middle one) to be the dominant bitch in the quintet.  She acts like my loeutenant bosses the others if theya re out of line and tattles on them :D

Having two bitches wouldn't be a problem generally.Brainless has explained it well. Bitches will have a hierarchy of whose the top bitch. If you consider bringing a bitch pup into your house with your five year old  then again you shouldn't have a problem. You were asking in your original thread if having a male with a bitch is a no no, and the answer generally is no. I have a lot of friends with one of each and theres never been a problem. The male does tend to try it on with the bitch (even if she's spade) but you'll find that you'll bitch as I said above will put him in his place.