Hi

Bit of an odd question.. I've been pondering it all night, and don't know the answer!!! 

Can dogs be identical twins???  I mean derived from the same egg and same genetic makeup? 

This might be a bit of a silly question, but I'm really interested and can't find the answer anywhere.  Surely someone, somewhere must have checked?

Please don't think me too strange for asking such a bizarre question, I watched a documentary on twins last night, and after studying Genetics at uni, I find identical twin studies in people fascinating, so was wondering about dogs!!

Thanks!!
~Clare

I would guess they can, but who would know? After all, even the (mercifully few) cloned animals don't resemble the 'parent' animal - different markings etc. The only way to find out would be to have each puppy DNA tested.

This is something I have been wondering about too as my girl delivered 2 pups which seemed to be together, but I was not quick enough to see if they were in the same sac. They are very similar, so will be interested to see how they develop. I do seem to recall reading somewhere, though, that dogs dont have twins.

Yes I think arriving in a single sac means they are from the same egg but of course I expect a twosome would generally burst their sac during delivery.

Thanks I'm assuming they can too, but I just thought someone might have tested.  Identical twins have revealed so much about human genetics, and the nature vs nurture debate - I guessed someone would have looked into it in dogs.  It would be interesting in the case of HD for example to see how much of the condition results from environmental factors.  So if identical twins were common (ish), you'd think someone would have looked into these things.  Oh well - maybe that's my calling in life LOL!!!!!!!
~Clare

Wouldn't you just count the placentas?  Not an exact science as idential twins can develop on separate placentas but if there is only one placenta between two babies it is an indication of identical twins.  It all depends how early on the egg splits as to whether 1 or 2 placentas develop.

I've read somewhere that non-identical twins can share placentas too , at least human non-identical twins can. This is annoying me now... stupid documentary channel
~Clare

When my niece discovered she was pregnant with twins, the medical staff told her that because the babies shared a placenta it guaranteed that they were identical. Sometimes fraternal twins' placentas are very close together on the uterine wall, but they aren't the same one.

Really? I've never heard of non-identicals sharing a placenta, would they share the same sac as well?

[Gone away to google and come back] :D

I've just looked this up now and I'v found that fraternal twins can look like they share a placenta but the two placentas are actually fused.  When 2 eggs are fertilised separately then everything else develops separately, i.e. placenta, sac, chorion.  For identicals depending when the egg splits depends whether the split eggs' placenta has already started to develop or not.  The later the split the more likely the twins will share a placenta.

JG you beat me to it :D

Just looked it up, thought I'd read it somewhere - it was found once (sorry - I remember random facts), so very rare .  But it did allegedly happen as twins were different sexes, so def. not identical - they think it was probably caused by IVF treatment (if it's true)...
Back to dogs though :) if not all identical twins share placenta (I think that's right? May well be wrong again though!).. might not be an accurate way of telling.. BUT - has anyone had any experience of puppies having the same placenta?  I guess we can be almost completely sure that they're identical?
~Clare    

Quite a fascinating question I would say! I don't see why it wouldn't be possible. Brilliant to study 2 such dogs as they grew up, and such fun if they were a marked breed like Cavs and would therefore have absolutely identical markings presumably! One to ask Steve Dean in his DW article A Vet's View perhaps? :-)

Well, as JG, has pointed out I don't think markings are entirely determined by genes I believe they are affected by what happens in the womb, temperatures, nutrition etc, so although likely to be similar might be rather different.  Similarly as soon as they hit the outside world, unless kept in strictly laboratory conditions, fed exactly the same diet and experience exactly the same level of excercise, social experiences, etc they won't really make any more of a control for each other than any other litter mates.

When my girl had pups last year there was only 4 or so (can't remember exactly) placentas for 8 puppies. When I mentioned this to the vet, she told me that pups often share a placenta and not to worry - having read "The Book of the Bitch" and many other breeding books I expected each pup to be born in a sac attached to a placenta. Well the first arrived as expected and from then on some came out with and some without, it wasn't just that I'd missed my bitch eating them, the placentas weren't there. Does this mean they were twins?

With my second litter of puppies when I had my bitch scanned I was told that there were two puppies in the one sac he described them as twins. When I consulted my vet as to whether this would cause any problems when giving birth he told me not usually but I could probably find that one of the puppies could be bigger as it was known for one pup to get more nutrition than the other. That was exactly the case, one was over half as big again however as they grew a problem arose with the bigger one, he developed a clicking noise when he walked and this turned out to be the bones in his shoulder clicking together as his shoulder had not formed properly, this only became apparent as he got bigger. They did however look very alike, same brindle markings and colour, very similar heads same expression, one just looked a bigger version of the other. The bigger one had eventually to be put to sleep as being a giant breed with the amount of growing he had to do there was nothing they could do to correct the shoulder.

In my first litter of Beardies there were actually two sets of identical twins one male & one female set It made life a bit diffcult when people came to see them & worry the pants off me re retained placentas dumb me though there should be one for each puppy even though there were two both in one sac. it did speed up delivery as the bitch had all 7 in 1 hour 15 minutes . Good job my vet is a close friend & put me straight She was amazed too they there marked the same 7 always slept together

Never had any more though

Weird Do you know if they were alike when fully grown?  Both in personality and looks?  Oh dear, bet I could ask you millions of questions, as I'm really really interested in this now.. but I'll stick to that one for now!!!
Thanks
~Clare

They were like peas out of a pod same temp & personalities despite the fact they lived in totally different environs & brought up differently. When they passed away they died within days of each other(from old age naturally to boot) The two boys were very laid back & gentle & the bitches were totally outgoing & in your face type dogs. My vet friend kept bringing students & other vets to see them LOL they even got a mention on Yorkshire TV as she was a PT TV vet back in the 70's

That's amazing!!  Especially them dying at similar times.  It is very interesting in dogs because it's likely they have different life styles - food, exercise, etc, whereas in humans most twins are brought up in the exact same environment. I wonder how common it is?  I'm guessing not very if your vet was so intrigued!!
~Clare

Genetically they will be identical which means that they will share the same characteristics inherited from each parent, so unlike non-identicals where one might have ears more like mum and the other more like dad identicals will be have exactly the same and so they should look the same.  As Isabel said though, the environment starts to have an effect before they are even born so if one is getting more nutrients than the other then they will be different sizes and their mental capacities might be slightly different.  Once they are born all sorts of things may interfere with development that will make slight differences between them such as how they interact with the mother, siblings and humans.  If a pup gets ill or injured this might affect their outlook and make them seem different personality wise.  I don't know about dogs and markings but certainly with humans if a child has a cow-lick at the front of their hairline the identical twin will have too. I would expect animals to be the same in that they should have the same markings but I don't know.

My son had identical twin girls in his class when he was at primary school.  I asked him if he could tell them apart and he said "Of Course! Michaella has a purple hairband and Asher has a pink hairband"  I'm such a silly mother :rolleyes: :D

Hair growth may be the same but I remember when that kitten was cloned, reading that its markings were different to its "parent" because this was determined by factors in the womb, I think temperature was mentioned, although it was tortoiseshell which may have this perculiarity uniquely.

Perhaps mine, then were just delivered together. They are both exactly the same size (even gaining weight at the same rate). As they grow up it will be interesting to compare them, but in my breed there are no markings. As pups they have dark masks and coat colour varies, and in that respect they are exactly the same, but only time will tell. They are just over 2 weeks now, so will see how they look in another 5 weeks.

http://www.messybeast.com/tricolours.htm if you scroll down the reason for Cc not being a torty is explained it is because they used an adult cell apparantly

Colour & marking inheritance in Beardies is a lot more simple than in cats. & some other breeds. Fir example in GSDs Black is the most recessive & a breeding of "white"GSD to another"white" GSD can produce blacks http://www.mayanser.com/gsd/info/Colour_and_Heredity_2.htm might be of interest

LOL then of course there is the"greying" or colour fading during development that is so typical of beardies. Good job you can tell from the colour of their noses what colour they really are ;)

That's certainly not what I read, but then it wasn't in a scientific publication they would just have been reporting what they had been told or understood :)

http://www.messybeast.com/catarchive.htm the whole site is very interesting

No question is silly it's all a learning curve, ask on  It's the only way we learn.

Warm regards Susan