Considering a Second Dog?
I get frequent calls and messages from families who have 2-4 dogs and they are all out of control. All dogs in the home have to be on the same level of obedience, as well as all the family members should be on the same page about dedicating time to training.
Before you add dogs to your family, make sure that the existing dogs are doing well. They don't need to be off leash trained but lets think about things before we add to the pack. If your dog is dog aggressive, it is probably not the best time to bring another dog into your home as you will most likely end up with dog fights, large vet bills and a trip to the ER for the humans in the home.
If you have a nervous, fearful, anxious dog and you add a dog into your pack to "help" the other dog get over the nervousness, sure sometimes having multiple dogs can help, but you may just end up with another nervous/fearful dog, as those behaviors are unintentionally reinforced by humans.
So what to do. Start with the rehab and training of the existing dog(s) in your home. Work on all of your obedience work, your behavior modification and your household management and get things running smoothly before you add any more dogs to your house.
I know your intention is to help more dogs, BUT, in the long run you are just hurting yourself and the dogs you already have in your home.
Chose a dog that will be compatible with your existing lifestyle. One that suits the energy level of the family. Don't get another dog thinking that it will give you an excuse to walk more. We all know it never happens.
Choosing a puppy. Please choose a reputable breeder, select a puppy suited to your lifestyle, and most of all be prepared for potty training, obedience, teach a pup to walk on a leash, and off leash, crate training, some sleepless nights while you are doing all this.
Rescue dogs are not a breed. Just because you did a humanitarian duty does not mean the Rescue does not need to be trained. More than any dog, a rescue needs structure, and consistent training. Rescue dogs, even shelter dogs, are most often turned out by the owners due to behavioral issues. Be prepared to train extra should the behaviors manifest.
With all these thoughts in mind, good luck with your new friend.