Getting a second dog as a companion for an anxious dog is a very tricky decision that must be well thought out. Unfortunately, it's much more common for anxious behavior to spread from the resident dog to the new dog than for confidence to flow in the opposite direction. You also have to consider whether the dogs will be safe if left alone together unsupervised, and most importantly, if your dog really even wants another dog in the home.
As always, I turn to my muse, Charlie. Charlie was an only dog for the first seven years of his life (all very heavy SA years). When we moved out of my mother's apartment and in with a friend in a roommate situation, we also moved in with my roommate's dog, Frog (don't you just love the name?). Charlie and Frog have similar social skills and preferences, they're both tolerant of most dogs, but have large personal space bubbles and don't really like to play with other dogs. They are both neutered males, within a year's age of each other. In other words, they got along really well.
It was also during this time that I really started working with Charlie on his SA and we got into clicker training (yay!). Over time I noticed a pattern that Charlie tended to be calmer and coped better when Frog's owner left him home with Charlie than when Charlie was home alone.
Charlie and Frog sharing the couch in our old apartment. It was unusual to see them so close together.
Since Frog's owner would sometimes take him to work, I ended up bribing him to leave Frog at home to give Charlie (and me) peace of mind. We barely ever saw them interact, a cursory butt sniff was the pinnacle of their relationship (OK they also loved to run after the "cats" in the alley together, and Charlie would always wait for Frog to initiate - kind of cute for a generally anti-social dog), but they definitely comforted each other when home alone together by merely being in the same apartment.
When it was time for Charlie and me to move out, I was understandably worried about losing a crutch and what I felt was a modest part of our training and rehab plan at the time, so I set out to find Charlie a suitable canine companion. Because Charlie is such a generally anxious dog I needed an uber mellow, relaxed dog who wouldn't feed off his waves of anxiety. I have a substantial soft spot for Pit Bulls, so went on the hunt for our perfect dog.
I met many, many dogs in the next few months, several of whom I was mildly to moderately interested in, but none of them "fit" the way I needed them to. I wanted a dog who would ignore Charlie as much as he ignored them - he doesn't care for jumpy, playful dogs, and unfortunately most Pitties are jumpy, playful dogs! I also didn't want a very large dog (at the time), and was looking at those below 40#.
We eventually made our way to Sean Casey Animal Rescue in Brooklyn. I spoke to the adoptions manager and explained (very verbosely and with many details) exactly what I was looking for. I had Charlie and my brother with me so we could properly assess Charlie's reaction to the new dog and vice versa safely. Without blinking the manager knew who he wanted us to meet and asked for "Sandy" to be brought out.
Out walked this tiny, red, skinny, stinky, scarred up Pit Bull and my first thought (I'll admit it) was how ugly she was! She was so calm as we walked around the block. She and Charlie sniffed each other for a second and then completely ignored each other for the rest of the walk (exactly what I was looking for) but were content to walk side by side (and even fell into step!). We brought her back and saw several other dogs, none of whom felt as good as she did (they were either too interested in Charlie, too hyper for his liking, too jumpy for his liking, or were so excited about being outside, being with us, they barely noticed as they bulldozed over him in their enthusiasm, etc.). My brother and I ended up comparing them all to the little red dog, and asked to see her again at the end (can you tell where this is going?). For the second walk we sat down on a bench and she crawled and mushed all over us and wiggled her way into our hearts, all the while being very mindful of Charlie (could this be real?). I didn't adopt her that day, but after forcing myself to visit a few other shelters and meet many more dogs, that weekend we busted her outta there. The rest, as they say . . . .
What a relationship built on trust looks like.
Unfortunately, later on I found out that Emma has substantial resource guarding problems towards other animals (as well as troublesome reactivity to some people), so I can't ever leave them alone unattended (especially since I feed them from frozen Kongs) - even with proper training it's just not a risk I'm willing to take (I'm happy to report that she's been great after a lot of training and hasn't guarded in many months!). So Emma is crated any time I leave them alone, but this arrangement seems to work well for Charlie. We've also acquired two cats in the past year, and we all live in a small NYC studio apartment together, but they're a well-chosen bunch and complement each other nicely. It's been a very long time since Charlie has been left alone (all alone) and I don't know how much the other animals really help him cope at this point, but I have come home many times to him sleeping on the bed with one or both cats.
How does this apply to you? Well, first get to know your dog. If your dog has excellent doggy social skills, doesn't get into fights or engage in inappropriate play with other dogs, this may be an option for you (you never want to leave two dogs unattended if either or both practices unsafe or inappropriate play behavior because that can easily escalate into a fight). It is of the utmost importance that you seek a professional trainer or behaviorist to help you choose your new dog because if you're trying to help ease your current dog's anxiety, you need to be sure that:
1) Your dog would welcome another dog in the first place.
2) You choose the new dog very carefully - this is not the time to get carried away by looks or breed, you need a very specific personality-type specific to your current dog.
3) Your home set up and schedule can accommodate a second dog.
4) You need to want the second dog too!
5) You get a dog of the proper age to most benefit your dog.
This is also not a good idea for dogs who are extremely anxious when left alone, currently not eating, damaging themselves, or destroying furniture, etc. This is a step to consider when you've already done a good deal of the work and your dog is experiencing much more "normal" levels of anxiety. It's simply not fair to either dog otherwise and I hope you take this warning seriously. This would never have worked for Charlie had we tried it five years ago and may have resulted in Emma developing anxiety.
If you feel, however, that you and your dog may be ready for an addition but if you're not sure how a second dog would fit into your home, or if you're ready for such a commitment, fostering a dog in need of a home is always an excellent idea. Contact your local shelter or rescue and see what type of programs they have. Some will even pay for all food expenses, and most pay for medical expenses. There are short term fostering options of just a few days and longer term fostering that can last months and even years. One plus side of many is that you're saving two dogs - the one in your home, and the space you opened up at the shelter for the next dog to come in. If you end up falling in love with a foster, you can always join the ever expanding pool of "foster failures" who go on to permanently adopt their not-so-temporary friends.
Be mindful though, that dogs coming from the shelter may be stressed out, which may affect your resident anxious dog and turn into a bubble of even more serious anxiety, so you please be sure to dull the edge of your resident dog's SA before trying this out (again, please seek the help of an expert!).
And if your dog likes cats a lot, maybe a cat friend is more her style!