A little background - 19 years ago I rescued my first Basenji. She was a great little special needs dog, but I felt bad leaving her home alone during the day. So, a year later I got her another Basenji playmate; Alex.
Cassie raised Alex almost like her own pup until Alex reached maturity. At that time, Alex became the dominate and very jealous dog. He became very jealous anytime Cassi got attention and he didn't, and would frequently growl at / attack her to demonstrate his dominance. A few of these demonstrations ended in bloodshead/stitches for Cassi. They lived together for 14+ years. Alex tolerated her for the most part, but the would not sleep together. They did both react badly if separated for any length of time - sort of like a grumpy old married couple.
Now we are in a similar situation. We've had Bella for a year now. I really think she enjoys being the center of attention, but I still feel bad when she's left home alone during the day (or while we're gone overnight). However, I can't convince myself that bringing another B into the situation would be better for her. Will they get long like best friends, or turn out like my previous two did? If I thought Bella would be just as well off by herself I'd tend to keep it that way. I'd prefer to be a one dog family at this point in my life. However, the thought of giving her a playmate and helping out one of the pups at the local shelter keeps crossing my mind.