To ensure that each puppy reaches his potential, everything needs to be done separately: walking, training, eating, and sleeping. If the pups are very young, sleeping together may be fine for a while, as long as they are getting enough one-on-one time with you, but before long they should sleep in their own crates.
Professional trainers like myself recommend against bringing home two puppies around the same age, let alone two from the same litter. While this sounds like a good plan in theory, in practice it often causes quite a bit of heartache and potentially some serious aggression trouble.
The recommended age for separating puppies from their litter is 6 to 8 weeks, according to Dr. David W. Reinhard, a consulting veterinarian for Nationwide pet insurance.
What exactly is “littermate syndrome” and is it real? Littermate syndrome can occur when two puppies adopted from the same litter grow up together in the same home. In some cases, these sibling puppies form such a deep bond with each other that they fail to properly socialize with people and other dogs.
FINAL THOUGHTS ON LITTERMATE SYNDROME
Make sure you bring each of your new family members home at least six months apart.
Early Indicators of Littermate Syndrome
Signs of littermate syndrome include fearfulness of unfamiliar people, dogs, and other novel stimuli (neophobia); intense anxiety when separated, even briefly; and difficulty learning basic obedience skills. In some cases, the two dogs will fight incessantly.
Depending on when the pup is rehomed, dogs can recognise their relatives later in life. If puppy littermates remain together for the first 16 weeks of the puppy's life before being rehomed, chances are they'll be able to recognise their family later on, at least for a few years.
Research suggests that dogs are able to recognize their siblings and their parents later in life as long as they spent the first 16 weeks together. Intuitively, the less time dogs spend with their families as puppies, the less likely it is they'll be able to recognize a family member later on.
Crate them separately.
You can certainly leave them together in their puppy-proofed space when you're gone all day, but they should be crated separately at night. You can crate them near each other, but this is the perfect time to start habituating them to not always being in close contact with their sibling.
So in short – yes, puppies miss their siblings at first. But they quickly get over it. Dogs don't really have the mental capacity to reflect on their early-life peers, so they won't really “miss” their siblings in the way a human might.
Dogs are social animals and usually happier around other dogs, but a second dog will never be a substitute for inattentive, absent or too busy owners.
Many people are hesitant to adopt a second dog because they assume it will be twice the work and twice the money. But the truth is, owning two dogs doesn't have to be more work – in fact, it can often be easier. And as for the cost, it will cost more money than one but not twice the amount.
For the happiest dogs and the safest household, opposite sex dogs almost always do best together. Many same-sex combinations of dogs will fight, sometimes to the death. Those who work out a dominance order may not fare much better.
Need for Alone Time
It is recommended to keep the puppies separated for most of the day, scheduling only a couple of set play-times. You'll therefore need to separate them.
Two littermates can form an intense bond, one that can result in the social exclusion of any other animals and/or people. However, this condition has been debated as both fact and myth, and many think that it occurs more in dogs since they are better known as pack animals.
Many puppies are separated from their littermates early in life, and they likely won't remember their siblings after about two years.
Fights between puppies are often a result of overstimulation, which can quickly happen with two puppies living under the same roof. This behavior tends to be particularly true for littermates of the same sex.
Start by establishing separate areas of the house for each dog using Dog Gates, Dog Crates or other equipment to keep them apart. Do not let the dogs interact again until both have a very strong understanding of the “Leave it” cue (see below). Above: Keeping dogs apart using a crate is a solid idea.
In dogdom, there's a turn of phrase called, "Second Dog Syndrome". This describes the process of adding another dog to the home quite well, but not necessarily in a positive light. As humans, we are bound to forget all of the time and effort it takes to raise a puppy right.
Other pets might bring some comfort to your anxious dog, but they won't cure their separation anxiety. Unfortunately, the short answer to the question “Will getting another dog help my dog with separation anxiety”, is usually no.
Many canine behavior experts feel it's best to rehome one of the siblings when a pair is showing early signs of littermate syndrome, so that both puppies have the opportunity to grow separately into stable, balanced adults.