Hi there,
Are your "babies" happy, relaxed and calm and are you "top dog". If so you can introduce a new dog no problem. I have an alarm bell ringing him my head at the moment due to the word "babies" - do you spoil them? - are they territorial of things and you?
I have four dogs and over the years have taken in strays, sometimes for 1 night, sometimes for months and I have never had a problem because if I decide to bring a cat, dog, person, whatever into my home then I can as I am pack leader and I treat my home and everything in it, plus all the dogs as my property so my dogs have to accept all my rules and decisions. If your dogs see you as pack leader they will accept a new dog.
I give them a long walk before bringing in a new dog so they are a little worn out and not so excitable, then I bring the new dog into the same room as my dogs - usually i walk away and leave them to it - you can affect the way your dogs react if you are in the same room and are anxious and anticipate problems - dogs pick up on this and can become anxious as a result. The least fuss the better.
don't let the new dog have the run of the house or give it affection in the first few days. If you want to show your dog around - take charge and go into a room first and "invite" the dog to follow. Show the dog where he is expected to sleep - I made this mistake once recently; my dogs live outside and I have four kennels, the new dog came home but I didn't show her where to sleep, assuming that she would just follow the others at bedtime - poor thing spent the whole night outside my front door!
I admire your bringing in a fourth, four is hard work - I can't believe how one more can make such a difference but I find it harder to walk 4 now rather than 3.
Good luck
