I’m working on a column for Bark right now about the ontogeny of fear in dogs. The editors, Claudia and Cameron (the editors of Bark), adopted two sisters from a rescue organization down south. The girls are litter mates who might be BC/terrier X beagle crosses. Both came under socialized and shy, but one (Kit) has rapidly come out of her shell, while the other (Holly) is still profoundly fearful of any kind of novel event. Leaving the house is a trauma for her, as is the appearance of any object that she’s not expecting. (Claudia’s purse fell off a chair and Holly refused to go anywhere near it, even though it blocked her access to her favorite area of the house. Meanwhile, Kit jumped over it and continued on her way.)
Claudia’s question to me, and the motivation for the column, is “What are the forces that have made these 2 siblings, who shared the same early environment, so profoundly different?” It’s a great question… and I’ve been doing some research I thought you’d be interested in. A longer story will appear in a later issue of Bark, but here’s a small piece of it: Evidence is increasing that in utero experiences have profound effects on an individual’s personality. Just look at these findings from human development:
1. Babies born of starving mothers are born with livers and pancreases that are less able to process fat and sugar, and as adults they are predisposed to diabetes.
2. A moderate amount of stress during pregnancy leads to a child who is more adept at tasks requiring reasoning and coordination.
3. However, extreme stress or trauma does the opposite, and can create a child with fewer receptors in their brain for the stress hormone cortisol. Once born, even as an adult, the child’s brain is unable to sense large amounts of cortisol until it’s too late. Suddenly swamped with cortisol, the individual responds to even mild changes in the environment with fear and anxiety.
Although the studies I mentioned are all on primates, there is a great deal of evidence supporting the same effect in a large range of mammalian species. Here’s where the recipe for differences in personality in dogs comes in, even in litter mates. First off, all litter mates come with a different genetic blueprint. Just as you and your siblings aren’t clones of each other, neither are puppies, even when they are born at the same time. Each set of genes is going to react differently to the environment, including the one that surrounds a pup as it develops in utero. By the time pups are born, they have had two very different sets of experiences. They started out with different genetics that effects how they respond to their early environment, and they each have had a different experience inside the womb. We may think it’s all the same in there, but developmental biologists will tell you that each fetus has very different experience than it’s womb mates. (I do apologize for the pun . . . but I just can’t bring myself to delete it.) Some puppies get more nutrition than others, some get better immune system protection, etc.
By the time a pup, kitten or child is born, they have both nature and nurture to separate them.
I knew some of this years ago when I was breeding, and will never forget when Pippy Tay was about 2 1/2 months pregnant. She had ripped a hefty patch of skin from her side in a classic “tent injury” that clearly needed a lot of stitches. (I just about fainted when I saw may dog looking like she’d been skinned. I called the clinic and said: “This is Trisha, the dog owner. This is NOT Dr. Patricia McConnell and I am FREAKED OUT!”)
After settling down, I talked to the vet for quite a while about her pregnancy, and what effect any drugs we’d use would have on her, and how stressful the procedure would be. I’d just finished reading about learning deficits in rhesus macaques whose mothers had heard loud noises randomly produced during their pregnancy, and was worried about the effect of treatment of her developing puppies. We elected to give her just a local anesthetic, I stroked and coo-ed to her during the entire procedure, and thank heavens, she seemed relatively calm during the entire procedure. After wearing a T-shirt for weeks to protect the wound, she healed with no complications. I relaxed and the pups turned out beautifully.
I do think, though, that’s it is a good thing I’ll never be pregnant now that I have this knowledge. I can just hear it: “Careful! Be nice! Mustn’t stress mummy! You know what the research says!” (Oh, wait, but the studies do say that moderate stress is a good thing! Shhhhhhhhhhhhhhh.)
I’d love to hear if others have had experience with litters whose mothers went through serious traumas. Of course, we’ll probably never know what happened to Kit and Holly’s mom while she was pregnant, but it is tempting to speculate that it wasn’t all good.
Meanwhile, back at the farm: Somewhere I have a print photo of Pippy with the T-shirt, if I find it I’ll attach it to this post. But for now, here’s Sushi, looking ever so stressed on the couch on a cool morning ….. Not a lot of stress there!
xx
Crystal says
Adds a whole new dimension to the puppy mill puppies, doesn’t it? In addition to growing up in a stressful environment, they also were born to mothers that were likely stressed.
Mateus Freua says
About this subject of how life in the uterus can influence the whole development of child and adult is really interesting the research presented in the documentary “Child of our time” of the BBC.
Susan Mann says
I remember reading that a cloned calico will still have a different coat pattern, that genes are only the start, its how the genes are affected by various environmental factors (chemicals, temperature, not sure what else) that is the “new age” in genetics. My current pup comes from a litter that was all girls, and I know the breeder was curious to how that might affect development. I’ve heard that females in a litter of mostly males, can often be “masculinized” in utero by the neighboring boy pups, but that it doesn’t necessarily happen to all the females in that litter. I’m wondering if differing amounts of testosterone in utero might have differing effects on the littermates? Not that we’d be able to find out, but something to wonder about, and I’m wondering if there’s any info on testosterone and estrogen’s effects on mediating the stress response?
Christine says
Our 8-month old dog doesn
Mateus Freua says
Christine and Trisha, about the fear of walking on certain floors is particulary interesting the work: Journal of endocrinology (2004) 180, 439-448.
Cynthia says
I wonder if there are any pictures available of their sister dogs? My dog is a terrier-beagle-collie rescue thing from the south as well. She also sports a high-strung, prone to anxiety temperament. Maybe there’s a whole clan of anxious dogs that look vaguely like our dogs running around the woods of the south!
Carol B says
I love your blog and books, and not that it has anything to do with the above, but I wanted to share…if you’ve not yet seen this You Tube, please check it out – it’s really something!
Wendy says
Another interesting post – thank you! I remember reading once that littermates could be as little as 18% genetically similar to their siblings. Of course I can’t remember where I found that – do you know if that’s true?
Rosana Hart says
What interesting topics! I have long been aware in humans I know, mostly ones in my family, of various connections between in utero experiences and later life… one good friend of my is phobic about nothing but snakes, and when her mother was in her 7th month of carrying my friend, she was badly scared by a rattlesnake in the mountains. I could tell stories like this all, and of course any given one of them proves nothing in itself. But a pattern emerges.
Kit and Holly… so interesting. I would imagine that somehow Kit fits more into your #2 category above, moderate stress during pregnancy, while Holly fits more into #3, more stress and thus more easily swamped by her environment. This during the same time in the same womb.
Wish I had a good animal breeding story to contribute but I’ve only bred llamas, and it’s rare for there to be more than one at a time. Ours were all single births. Dancing Cloud and Rennaissance were high strung like their mother Posey… Lallapaloosa was mellow like her mother Lil Bit. No surprises there. Dads contributed less to temperament.
Cindy Bartels says
A stray dog came to us pregant and gave birth to a litter of 8 – 7 survived. We adopted out 4 and kept 3. Of the two females and 1 male we kept one of the females has a very nervous, timid personality. All 3 had the same environment, reinforcement etc. growing up but even at age 10 she still has less confidence than the other two. I have often wondered what made the difference…. all 3 get lots of love etc… she has just always had a nervous personality since birth. Reading your blog makes me wonder if perhaps it was some variant that she reacted to invetro.
nan marks says
Fascinating topic I look forward to your article. (and you may just have explained my sister’s otherwise inexplicable diabetes). I can offer one story. We took a dog in at the shelter–best guess a malamute/siberian collie cross–along with her litter of five. She was severely underweight, tick infested, matted, and basically in terrible shape. The person bringing her in said he found her and the puppies in the woods (mysteriously he walks the woods with a rope and a card board box and acquires a starved stray who thinks it is spiffy for him to leash her up and take her pups). The pups were very young (fairly normal weight). The mom was with us quite a while both to raise them and because she looked like a very big black starved wolf which did not appeal to the average suburban adopter. We soon realized that she was a supurb dog. Balanced in disposition, confident but never pushy, very bright (she figured out how to open the kennel door–rare but not unique–however she would push it shut to keep her pups in, she’d open cubboards and then close them . . .). In the dog yard she was calm and relaxed but if any dog to dog thing broke out one glance from her and they’d quiet down and separate. an alpha in the best sense of the word. I placed her with friends of mine and she remained that way throughout her life. Nothing phased her, many things interested her, and her actions were insightful. She had five pups. I took one of the five hoping she would have much of her mother in her. I stayed in touch with 3 of the other 4 pup adopters. All of the puppies were in excellent homes with good attention paid to socializing them. All lived successful pet lives but all showed some issues around fear, 3 of the 4 had some resource guarding, 4 of 4 were dogs that were a little iffy around some other dogs and around unexpected or different looking humans. None had the calm balance, adaptability and intelligence of the mother. Who knows, of course, what the father brought to the table but I’d say there is certainty that the mother was in fairly extreme conditions during her pregnancy as were the pups in utero.
Trisha says
Susan, re ‘masculinized’ females. You are indeed right that androgen (a precursor of testosterone) can permeate through the placenta wall and effect the development and subsequent behavior of females in utero. I talk about it in more length in the Bark column-to-come, so stay tuned. I don’t know the research on T and E and stress responses, interesting question. Anyone?
Christine: Don’t despair, dogs usually start to generalize after 5 to 7 exposures (to say, 5 to 7 different areas of concrete). Just tell your dog to read this….
Mateus: What a great tip for us! Thanks so much. I’m looking into it this weekend.
Wendy: 18% shared genes between litter mates? I don’t know myself, but given how much shuffling there is in the re-combination of sexual reproduction, I wouldn’t be shocked. (do keep in mind though that some genes are more equal than others! “Regulator genes” for example, play a huge role in the activity of other genes, so part of the question is which genes are shared, along with how many…
Rosana: First, can I come pet your llamas? Something about those regal heads…. Second, interesting comment about disposition being primarily from the mother. Humm… anyone else want to chime in on this?
Nan: Fascinating story about the rescued dog (love the image of the guy who just happened to have a box and a leash in he woods with a stray who inserted her head into the loop….). I have to say she sounds really wolfie, because of her problem solving ability and natural ‘alpha’ behavior. Interesting about her pups. Could well be just the influence of the father (shyness is genetically ‘conservative’ or prepotent, and is easy to pass on) or just the dam’s experience while pregnant, or most likely some of both.
Christine says
Mateus: What an interesting article! Thank you for the tip.
Trisha: Thank you for cheering me up! I
Dena Norton says
Christine, I wonder whether the “expanse” of concrete or tile somehow reminds the dog(s) of an expanse of water.
Esther Essinger says
Thank you for this beautifully-written and fascinating article. (I especially love the pun , so glad you didn’t delete). I love dogs too and have been owned and trained by German Shepherds all my life. And so, my experiences in the sphere of dogs are quite incredible because of the traits of this particular breed, my lifetime favorite although I love them all. I also have been pregnant and had babies so my feelings in that zone are strong too. Thanks so much, I look forward to reading more of your excellent thoughts!
Good Shepherd Dog Obedience says
Fascinating article. Have a client with a highly reactive American Bulldog, dog aggressive with little impulse control. Sent her some info. saying perhaps females in utero with males can absorb more testosterone and become more aggressive. She texted back that her girl was the only female in a litter of thirteen!
Also, trying to find the perfect pup because my “herding” German Shepherd Dog (see Carl Fuller, Kirschental line) is older and will need to retire soon. She has that genetic obedience and insight that helps her to know what I need and do it w/out any training. She is my training partner in the fullest sense.
I hope to learn all I can that might help me to find/choose the perfect pup.
Thank you for any info. that might help my search.
Rosemary Robinson says
This is very interesting! I adopted two siblings from Spain three years ago. Their mother was a hunters dog and I know they have horiffic lives. My boys came to me when they were 7 months old, quite fearful and worried, which you could put down to a long journey, new environment, new country, new people they didn’t know, the list goes on.
However three years on and they are still the same or worse even. Edward is extremely highly strung, seems worried all the time, Jacob is much calmer now but if a sheet of paper falls on the floor he freaks!
He will not pass a new object in the hall etc, reading your article was like reading about my dogs.
I’ve had dog trainers out, tried a few methods but they are basically scared of everything and they have the best lives.
Trisha says
To Rosemary: Argh, poor things! (And you too.) I’d look at their physiology… is there anything you can do, food or supplement wise to help their internal states?