Are Two Pups Better Than One?

The pros and cons of adopting littermates.


hear it all the time: “Honey, maybe we should get two! Look how much they love each other! How can we possibly split them up?” 

My family and I frequently foster litters of rescue puppies, and when approved adopters come over to make that big decision – which one will it be? – the conversation often takes this detour. Watching two darling pups snuggling or romping together, somebody says, “Why don’t we just take two?”

It’s a natural impulse. In fact, keeping littermates together was very much my own hope when we fostered our first litter almost a decade ago. Back then, when a potential adopter epressed an interest in getting two pups, my heart raced. Think of it: Little Ben and Pretty Girl, together forever! I loved this idea! The advantages quickly added up in my mind:

* The transition would be so easy! No sad pup crying through those initial nights without the warmth and company of littermates.

* The pups would be so happy to have a friend to play with every day. 

* There would be guaranteed exuberant exercise, which would decrease household destruction and mouthiness.

* The owners would be less stressed by the demands of puppyhood because, rather than having a bored puppy constantly seeking their attention, they’d have two pups pretty darned content with each other. After all, I vastly preferred fostering two pups to one, because it was way less work for me. 

Filled with excitement, I let the shelter know that one of our potential adopters wanted two puppies. Their response? “We don’t actually adopt out littermates together.” I was stunned. What kind of anti-puppy-happiness policy was this?


It turns out I had a lot to learn. While every one of the bullet points above is true, there are even more bullet-point reasons why most dog trainers and animal shelter professionals recommend against adopting littermates, including: 

* Puppies need to learn to be alone. One of the key things I try to teach my foster pups is that they’re okay without their littermates. If I were to let them hang out in the same room with their mom and siblings every single minute for eight weeks, then adoption day would be terrifying for them. In the beginning that means simply holding one pup outside of the puppy pen for a moment, and immediately returning. Then I might take just two pups into the kitchen to play while I do the dishes. Finally, I’ll take just one pup upstairs with me to hang out with a chew toy while I work on the computer. 

Adopting siblings can delay this vital bit of the puppies’ education indefinitely. Now there are two pups who may have never taken one breath when they weren’t next to another pup. The longer that goes on, the more deeply attached they become. Some owners realize they have a giant problem only months later when they casually separate the pups – perhaps for a vet appointment – and find both dogs in an absolute panic, destroying walls and escaping from crates.

Littermates Twilight and her brother TikTok joined a family that includes anther dog and three cats, so the duo is rarely alone together, and each gets critical one-on-one time with their human.

Of course, you can combat this issue just the way I do with a litter at my house: by making time to take each pup alone somewhere, every day. They need to have regular, varied experiences where they are separated from their siblings: in the house, on a walk, in the car, on a playdate. If you have the time and perhaps the household structure to allow that, this may not be a problem. However, experienced trainers and shelter staff will tell you that  most owners find they barely have time for one pup, much less two – even though they thought they were prepared.

* Having an always-present playmate isn’t enough to properly socialize a puppy. Daily play with a live-in packmate helps tire out both puppies, which is great – but the giant downside is that, without the urgent impetus to find another puppy or dog to help tire out a singleton pup, owners tend to get complacent. 

A lone puppy’s chewing, biting, and jumping will push a good owner to seek out other dogs to exhaust the little guy, which enlarges the pup’s world beautifully. There is far greater value in playing with all kinds of dogs – big and small, runners and wrestlers, floppy-eared and pointy-eared. They each play differently, and by interacting with a number of play partners, a pup learns a more nuanced, expanded language of doggy communication. That, in turn, makes the puppy comfortable with future dog encounters – on leash walks, at your sister’s house for Thanksgiving, at the beach with your friend’s dogs. 

In contrast, the littermates who play only with each other may well end up being dogs who can play only with each other! Unaccustomed to play styles they are unfamiliar with, less-socialized dogs may take offense at playful overtures from dogs who are new to them, and erupt in defensive aggression out of fear.

Again, an owner who is well aware of this issue can completely mitigate the effects by arranging for plenty of play time with other puppies and dogs as the puppy matures. 

* When people own two puppies, they tend to take the pups on fewer walks and adventures. When I first started fostering, I was always drawn to the adopter whose application mentioned their big fenced yard. Sure, the city apartment dwellers said all the right things, but then I’d think about this little pup who’d have to go down an elevator and then pass strangers and hear loud trucks every time he just had to pee! “Poor pup,” I thought. 

I’d like to slap my old self. I’ve learned over the years that those city dogs become fabulously socialized! Because exposure to all of those things is an automatic part of their life, they inevitably become incredibly relaxed about it all. It’s wonderful. 

What does that have to do with littermate adoptions? Well, often littermates don’t get out into the world if they live in the same house. They are nicely tired from all of their playing, so they don’t nudge their owners into walks. And even if they do, sometimes the owner remembers that last walk where two dogs were awfully hard to manage and opts out. 

Again, the dedicated owner will get around this by remembering how critical it is to get a young pup out and about in the world and will make the time (and enlist the helpers) to make adventures into the wider world a regular part of the routine for both puppies – preferably, one at a time, for most of those walks. 

* It’s more than twice as hard to train two puppies than it is to train one. I love to teach young pups to sit, stay, spin, touch, and shake. In fact, I really can’t help myself – whenever I have just one pup here. But if I have more than one pup? The best I can do is “sit.” I’m a dog trainer, for goodness sake, and I can’t teach two dogs a new thing at the same time. 

Teaching well requires giving split-second feedback to the dog. When you have two dogs doing different things, the feedback loop becomes meaningless. “YES!” you say as Pretty Girl sits nicely. But Little Ben heard that too, while he was jumping up on you. Hmm. What exactly did he just learn? 

To train two pups, you need to separate them. And perhaps the trainee needs to be out of earshot so that the distressed barking of the left-out pup does not distract our student of the moment. Do you have a set-up where you can easily take one pup away and work with her a few times a day – and then turn around and do that with the other pup? Can you sustain that for a year? Maybe you can! 

But most can’t, and, sadly, what often happens is that an owner calls a trainer in tears, reporting two completely unruly 9-month-old dogs who “can’t” be walked. The pups are bonded strongly to each other, but not with the owner. It’s a heartbreak that often results in one, if not both, being rehomed. 


Lots of individual training plus the owner’s robust support system has made the adoption of brothers Bristol and Bedford work beautifully. They are each other’s best friend and comfort – but they also settle down just fine when separated.

Trainers and shelter staff will almost always advise against a littermate adoption; instead, they frequently give the very sound advice to simply wait a year, so that your well-trained adult dog can set a fantastic example for a new pup. 

That said, taking in two siblings might be the right decision for you. The key is to be fully informed about the tricky issues and committed to a plan. When that happens, it can work out beautifully. 

As I was preparing to write this article, I reached out to a handful of people who adopted littermates from my rescue group. Every one of them wrote back using exclamation points about how much they love their doggies and how the double adoption was the perfect approach for them. My follow-up questions revealed that these folks truly walked the walk. They’ve poured a lot of time and resources into these pups, carefully shaping their experience so that each dog is well trained and confident on their own – and also darling together. Clearly, it can be done.

Even so, any time I hear an adopter say, “Hey honey, how about two?” I’ll still suggest my very favorite option: “Do you have a neighbor who needs a puppy?” That’s the best of all worlds: each of the pups will have a buddy close enough so they can get happily tired from everyday playdates, the owners can get little breaks while their pup is visiting next door, and each puppy will get plenty of individual attention back at home. 

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Kathy Callahan’s new book, Welcoming Your Puppy from Planet Dog, is now available wherever you buy your books. Certified as a dog trainer (CPDT-KA) and licensed as a family dog mediator (LFDM-T), Callahan specializes in puppies. She and her family have fostered 225 of them in the past decade, and her business, PupStart, is focused on puppyhood coaching. The podcast Pick of the Litter is Kathy’s newest effort to help people and their dogs live more happily together. Kathy lives in Alexandria, VA, with her husband Tom. They’re technically empty-nesters now since their grown daughters have moved on, but the house is still very active thanks to the four family members who were foster-fails: Mojo the German Shepherd/Akita, George the Great Pyrenees/German Shepherd, Kreacher the Chow/Beagle, and Mr. Bojangles, the best cat in the world.


  1. I kept three from a litter I fostered and it was a wonderful decision. Unfortunately one died at a year when I had them all neutered. However, the other two lived to be 16 and were very sweet and socialized. I could take them on trips separately or together and they were sisters to my human baby and helped me raise her. They were also very welcoming to several dogs and cats and birds that I also adopted. I would do it again if the need arose. I guess it depends on the dogs and the owners. Maybe we were just lucky but it was a very happy experience

  2. I keep hearing about a so called “littermate syndrome “. I suppose it is what is listed in this article. The only difference is that “aggression” from the dominant sibling usually happens as they get older.

  3. We had 4 doxies, two littermates, and two more littermates one year later. It was a wonderful experience! They all had their own personalities, and were great together. two were more attached to my husband and the other two gravitated more to me. We walked them all together and it was fun! It wasn’t any problem and we loved having all 4! We now have one 10 month old Basset Hound and will soon be bringing home our 2nd precious 8 week old Basset pup. We are 72 yrs old and looking forward to more fun!