Cavapoo Littermate Syndrome – My Personal Experience

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Most people have never heard of the term ‘littermate syndrome’. I must admit that until a few years ago, I had never heard of it either.

What is Cavapoo littermate syndrome and should you be concerned when buying two siblings from the same litter?

Below are my thoughts and experiences from owning dogs all my life and presently owning two sets of litter mates. They are my opinions so feel free to not agree with me.

What Is Littermate Syndrome?

Littermate syndrome apparently happens when two puppies from the same litter are purchased and then raised together.

They then form such a strong bond with each other that they don’t interact with their owners like they should, ignore any corrective discipline and are fearful of strange people and other dogs.

The two pups could also fight aggressively with each other.

Cavapoo Littermate Syndrome, Myth or Truth

I want to start off by saying that there is absolutely no scientific proof to back up the fact that littermate syndrome exists.

However, some aspects of it are worth taking note of and need to be taken into consideration but not because of the term ‘littermate syndrome’ but because raising puppies is not always a walk in the park irrespective if your pups are siblings or not.

People are quick to jump up and say, littermate syndrome, when two puppies are fighting, have separation anxiety, don’t bond with their owners or begin to show behavioral issues.

Should we say the same if a set of human twins display similar behavior? Should we then give one human twin up for adoption to stop the fighting?

This sounds ridiculous doesn’t it because we would never do that would we?

We would discipline our human children, teach them how to behave and spend time with both of them separately to correct their behavior and to bond with each of them. We would not just give up on them, split them up and send one away.

The same applies to puppies.

Another thought – what happens if you get a second puppy of a similar age from a different breeder at the same time? Would this fall under littermate syndrome?

Again, why then do breeders keep litter mates for future breeding and showing if this was such a big no no and will spell disaster?

There have been many success stories of litter mates been raised together and there have also been many stories of litter mates not working out.

But I firmly believe it is not about whether your two puppies are siblings but more about how you raise them that is the issue.

Bear in mind that some dogs just do not get on with each other never mind if they are siblings or not related at all and whether they are the same age or are years apart.

Having two successful sets of litter mates I would like to offer some advise and guidance when purchasing two pups at the same time but first let’s discuss what this syndrome is and why it has become such a big statement.

Signs of Littermate Syndrome

When the following happens or is observed then behaviorists and trainers immediately attribute this to littermate syndrome.

  • Failure to bond with their owners
  • Separation anxiety
  • Fear of strange dogs and people
  • Disobedience
  • Fighting and aggression between the two pups

Most of the points (except the last one) above can happen if you own only one puppy so saying that these wrong behaviors are because of littermate syndrome does not make sense to me.

Two Puppies From The Same Litter – pros and cons

It is very tempting when viewing a litter of puppies to decide to take two instead of one.

After all puppies are so cute and absolutely adorable when they are so young so it is hard to resist the urge to take more than one.

There are pros and cons to doing this.


  1. The most obvious reason to buy two pups is so that they have each other for company and this is true to a degree as dogs are pack animals and prefer not to be alone.
  2. They will exercise each other because they will play together and chase each other around
  3. To avoid separation anxiety as they will have each other when you are not at home
  4. You love dogs so much, you need more than one to shower your love on
  5. You can potty train both at the same time instead of going through the process again when you get a second pup later on
  6. Having two puppies is double the fun
  7. If you have children then there will be two puppies to share among them


  1. Two pups mean double the cost for vaccinations and worming medication
  2. You will need someone to help you when taking them to puppy class
  3. Twice the amount of poop to pick up
  4. Double the amount of food to buy
  5. Because they are of the same age then when they are really old then they could pass away quite close to each other leaving you with double the heartache

My Experience With Littermate Syndrome – My Cockers

When I was looking to buy two Cocker Spaniel puppies, I had no idea about littermate syndrome. My thinking was that it would be easier to raise two at the same time.

We bought Charli and Bailey (2 sisters) from a breeder that I had known when I was participating in dog showing. I knew her dogs well and I knew that she bred for temperament and size.

Some Cocker Spaniels are huge and I wanted smaller ones but more importantly I wanted ones with great temperaments because Cockers can be snappy.

We collected them just before Christmas on the 21st Dec 2018. They were 8 weeks old and just as cute as anything. Below is a photo of them.

Cocker spaniel pups
Charli (More Black) and Bailey (More White)

I excitedly took them to my Vet for a checkup and left in tears when she was so obviously against me buying two puppies because of littermate syndrome. I was shattered. This was the first I heard of it and I was devastated to say the least but there was no way I was going to return one.

How was I to decide which one would go back? I was already so in love with them.

I decided to do lots of research and speak to other breeders that I knew. They encouraged me to keep both of them and gave me excellent advise on how to raise them. There was hope.

Here is basically what I did –

  • I let them sleep together at night. It was easier on me as they never cried except when they wanted to go potty.
  • I spent time every day playing separately with each of them. I left one alone in the playpen and took the other one outside for one on one time and then swapped them around.
  • My sister trained Charli at puppy school while I handled Bailey. We trained on opposite sides of the grounds away from each other.
  • I took each one alone on walks. I would take one and leave the other one behind and then go out again with the other one. If my sister was available then she would take one while I took the other but we would go different routes so that we did not walk together.
  • I let them eat together as I did not want to encourage food aggression and all my dogs eat together.
  • As I watched TV at night then I would have Charli or Bailey on my lap and my sister would have the other one on her lap.

Doing this gave each of them quality time with us and times when they were alone without each other. It was hard work but it paid off big time.

Charli and Bailey are now almost 4 years old. I never ever had aggression problems with either of them. They have each developed there own characters and they are very bonded with us.

They are great with other dogs and are a pleasure to own.

I often come home to find Bailey in the lounge and Charli exploring outside or visa versa. They are comfortable being separate from each other and do not freak out if I take one of them to the Vet and leave the other one behind.

Bailey is gentle, sensitive and wants to cuddle. Charli is our wild child. She is stubborn, pushy and determined to get what she wants. They could not be more different in looks and character.

However, Bailey is the pack leader and Charli respects her and listens to her.

I love them dearly.

Charli and Bailey
Charli (front) and Bailey (at the back)

Littermates – My Cavalier King Charles Spaniels

We had our names down for a Cavalier King Charles male before we even bought the two Cocker Spaniels. One night we received an SMS letting us know that there were two Cavaliers available if we wanted to go and see them.

We went to see the litter that weekend and ended up taking both males.

As we now knew how to raise two pups, we followed what we had done in the past.

Cooper and Tucker
Cooper and Tucker

Raising these two boys has been just as successful as with Bailey and Charli.

Each boy has there own character. Cooper is a big softy and would make an awesome therapy dog. He just wants to kiss you and lie on you.

Tucker is more adventurous and is my shadow. He follows me everywhere and will even choose me over spending time with the other dogs.

Again, both dogs are very bonded to us yet enjoy each others company. There has never been any aggression between them.

Important Take Aways About Cavapoo Littermate Syndrome

Yes, you can most definitely raise two siblings from the same litter but it is very important that you do it responsibly.

  • If you want to buy two pups so that you don’t need to spend time with them and they can look after each other without much involvement from you then please do not do it. You are inviting major problems.
  • You must be prepared to put in the work and spend alone time with each pup every day.
  • I strongly suggest puppy school – it gives them confidence and the trainer will help you with them. You will need someone to handle one of the pups.
  • Walking each puppy separately has to happen. It is really important.
  • Only buy from a reputable breeder that breeds for temperament. This sets you up for success.
All 4 cavapoos together
All four dogs together. The crate door is open. They chose to lie with each other.

Photo of author


Irma Bense is an experienced dog owner with over 43 years of experience with dog showing, dog breeding, dog training and general dog ownership. Her love for spaniels also includes the Cavapoo, a wonderful mix breed between a Poodle and a Cavalier King Charles Spaniel. Presently she is the proud parent of two Cocker Spaniels, Charli and Bailey and one Cavalier King Charles Spaniel called Tucker.

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