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epigenetics and dog breeding mum and pup

Epigenetics & Dog Breeding: Why This Has To Be On Your Radar

by | Dec 15, 2021

Epigenetics is the study of how behaviour and environment can influence the expression of how genes work. 

You may wonder what on earth this has to do with dog breeding, but I urge you to stick with me – because what we breed from, dictates what we produce.

Environmental factors can alter DNA, which can cause life-long epigenetic alterations. 

This links into temperament testing before you breed and having a full honest appraisal of your dog (and your chosen stud) before you breed, so you can match a pair of dogs that are fit for breeding from. 

You need to consider epigenetics to breed well-rounded pups. And this is why epigenetics is so, so important for us as dog breeders to understand. 

A brief intro to the science of Epigenetics

Before we get into the practical elements of temperament and epigenetics in dog breeding, we need to understand what Epigenetics are in a little more depth.  

Your dog’s DNA is coated in organic molecules that are chemically attached and can influence the expression of genetic information. Environmental influences and behaviour, such as poor nutrition, stress and fear can cause life-long genetic alterations.

dog DNA epigenetics


Cells are fundamental working units of every being. All the instructions required to direct their activities are contained within their DNA.

They’ve all got a function, and they are all formed and dictated to by DNA. 


DNA is made up of four bases. Those four bases are adenine, cytosine, guanine and thymine. (Abbreviated as A, C, G, and T.)

DNA sequence

DNA sequence or the order, of the bases, A, C, G & T is what determines our life instructions. They are in effect the “ladder steps” of DNA. 


Genes are specific sequences of bases that provide instructions on how to make important proteins. These proteins are complex molecules that trigger various biological actions to carry out life functions. 

DNA Methylation

DNA methylation involves the attachment of small chemical groups to DNA building blocks. It is through this process that genes can be turned off or silenced, resulting in no protein being produced from that gene.

Epigenetics affects how genes are read by cells, and subsequently whether the cells should produce relevant proteins. It can effectively switch them on or off.

Epigenetics Is Everywhere

Phew, that’s the science out of the way! Let’s get back to how this is relevant to dog breeding. 

What your dogs eat, where they live, who they interact with, when they sleep, how they exercise, are all factors that cause chemical modifications that have the ability to turn genes on or off.

Environment and behaviours can influence epigenetic changes, affecting how a dog’s genes work. This is incredibly important to consider for the dogs we breed and breed from.

What we breed from, dictates what we produce

Health testing may have been on the agenda for dog breeders for a long time, but we need to be going further than that. 

The temperament and life experiences of both your Dam and Stud dog will have a huge impact on the puppies you produce. Assessing temperament alongside health is critical to the future of our dogs. 

If you’re critical around what you’re breeding from, you’re going to improve it. And that’s good news for dogs, families and rescues everywhere. 

Sometimes being critical means looking at it from a 30,000-foot view. You need to be able to consider your dog without bias. 


Your dog may be perfect for you, and ideal in your home, but if you put her in a house with four small children, does she run scared? Or if you walk her in a field full of sheep, is she going to be able to come back when called and ignore them?

The inherited bark

As a Poodle Cross breeder, I quickly realised about 17 years ago that the poodle that I was breeding from was really noisy.

He constantly had something to say. His name was Stanley. If you said to him, ‘Stanley, be quiet’ he’d bark back at you and say no! He couldn’t be quiet, he had far too much to say!

I can’t imagine where he learned that from!

So then I started to notice that his puppies were chatty. They were really squeaky when they were feeding. And as they got older, we were socialising them and handling them, and they were so squeaky and noisy. Then they too started barking….

Then they would get into their homes and they were loved and adored by their families, but the feedback was always the same. The dogs were making a lot of noise! And that’s not a coincidence!

That’s epigenetics at play!

What to ask yourself about the dogs you’re breeding from

Our biggest concerns are to consider the key behaviours that can lead to dogs ending up in rescue – most commonly this will be reactivity issues or separation anxiety. 

So, with a critical approach ask yourself some questions about both potential parents. 

  • How’s your dog around children, other dogs, strangers?
  • Is your dog noisy?
  • How is your dog going to the groomer or the vets?
  • Is your dog ok with livestock?
  • What doesn’t your dog like?
  • Does your dog resource guard?
  • How is your dog when left alone?
  • Is your dog fearful of anything?
  • How does your dog respond to surprises, like sudden noises for example?
  • What experiences has your dog had previously?

dog and child

Creating an evidence portfolio for stud dogs

When we discussed epigenetics in a recent live masterclass, a concern that many breeders had was how to thoroughly assess whether a stud dog is suitable to pair with for mating. 

If you’re a stud dog owner, then create a video compilation of your dog in various certain situations and show your dog’s temperament off. Allow the breeder you’re partnering with to see your dog in a variety of situations, so you can both make an informed and educated decision before proceeding. 

Consider showing how your dog responds around livestock, children, loud noises, other dogs and so on. 

Demonstrate how your dog is naturally in the home, out on walks, and in new environments. 

When owners of both stud dogs and bitches are approaching the breeding process from a place of honest intention to breed only the best dogs together in terms of health AND temperament, we are making huge leaps for the future. 

Epigenetics and your pregnant dog

Epigenetics suggests that EVERYTHING your pregnant bitch is exposed to can affect her unborn puppies.

  • What she does 
  • What she eats 
  • Where she lives 
  • Who she meets 
  • What she is being exposed to 
  • What she HAS BEEN exposed to

The experience of your dog during pregnancy has a direct affect on her puppies in utero. Diet, stress levels, and her overall physical and mental health will have a huge impact on the puppies you bring into this world. 

The Cherry Blossom Experiment

The Cherry Blossom experiment demonstrated how powerful epigenetics and life experiences can be for future generations. 

Dias & Ressler’s taught two groups of male mice to fear odours by zapping their feet with an electric shock every time they blew scented air into their cages. 

The experimental group became afraid of cherry blossoms. 

After three days of fear conditioning, the cherry blossom mice later reproduced. Having grown to adulthood, the resulting offspring had a heightened jumpiness to the cherry blossom smell, despite never having been exposed to it themselves.

The researchers also artificially inseminated females using the sperm from the original fear-conditioned mice to eliminate any possible socially transmitted effects between the fathers and the females. 

And guess what? The results were the same, suggesting epigenetic inheritance rather than environmental experiences were at play. 

What does this mean for dog breeders?

Puppies are NOT blank canvasses. Their environment, even prior to birth, forms them in their very essence. We must start as we mean to go on.  

Anxious or fearful pregnant dogs are more likely to breed anxious fearful puppies.

So using fear/anxiety as your main considerations, consider your bitches temperament.

Is she a nervous stressed dog to start with? Is she reactive in certain circumstances? What is her environment like?

By being completely honest with ourselves before deciding to breed, we can make life better for both our own dogs and those of the future. 

In Conclusion

Epigenetics is a vital component of breeding better, more temperamentally robust dogs who can not only cope, but thrive in a human world. 

The temperament of your dog isn’t testable in the way that health conditions are. We can’t test for it, so we have to be observant, critical and realistic about what we observe in our dogs.

Statistically, the majority of dogs that end up in rescue land there due to behavioural issues. 

When we start with a foundation of sound temperament and raise our puppies to nurture the positives they’ve inherited, we start them off on the best paws possible. 

Next, we need to match our puppies with the right owners for them. And that’s where Puppy Profiling comes in. 

When you match your puppies with their new owners based on personality, lifestyle and temperament, you set everybody up to succeed. Unfortunately, new dog owners often choose based on looks, so they need YOU to guide them on selecting the right puppy for their lifestyle, family and expectations.

Learn how to master the art of observation and pair your pups with their perfect forever homes with our puppy profiling course for dog breeders. 

Rebecca Walters

I’m Rebecca Walters, founder of Pupstarts Breeders. I’m a 5-star licensed dog breeder, an ex-licensing officer, and a woman committed to changing the industry for good.

I want to deliver all the dog breeding information, advice and education you need to be an ethical and reputable dog breeder who makes a difference in the world.

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