Hi Claire.   Dogs are a pack animal.   They do need that company around them.  At the moment, you are her pack and her leader.  However, when you are not there, she may fret especially if you are away for long periods.  To get a companion for her would definitely settle her and help her when she is by herself.  However, so that Zoe remains settled and does not start to become jealous of the new dog, the new dog must be put on the bottom rung of the hierarchial ladder.  Zoe gets fed first; she gets petted first, etc, etc.  This will keep the household on stable ground.  To answer your question, in my mind two dogs are better than one.  A few reasons are:  they are company for each other,  they reduce your need to go for long walks because they will chase each other for 5 minutes (which is the same as a 30 minute walk).  And, the extra work looking after 2 is minimal.

I hope this answers your question fully.

Yours faithfully,  Paul,  Altiquin Dogs

altiquin@esatclear.ie