Thursday, December 10, 2015

Identical Twin Dogs? It's Rare but Possible

I posted this originally in October of 2013, saying that identical twin puppies delivered in a single amniotic sac rarely if ever occur.  Well… I stand corrected. Several people have responded to the post describing identical twin pups in one of their litters.  This is what they said:

"I  have to say that until it happened to my dog, I never knew it could happen. 2 puppies, one sac with umbilical cord going from puppy to puppy and a 3rd cord going to mom. It looked like a Y or T. I just buried the babies as they did not survive. I could seal them up and send them to you if you wanted to see this yourself. Shocked the heck out of me - a seasoned and experienced breeder. My vet says this does happen just not very often."Anonymous 4-25-2015

"My dog had a litter of 15 on 11/12/15. She had a set of twins at 7:57am. 2 pups, one male on female, come out the same sac attached to the same placenta. So yes, it is possible! I couldn't get a picture as the mother quickly tended to them. The female twin is very tiny about a third her twin brothers size but she is doing well and is definitely a fighter."Samantha S 11-15-2015


"My dog just had identical twin girls, she had a couple of hours after birth of first pup, then delivery of second was much more of a struggle. When it finally came out she got straight in and began cleaning the sack away so I never got a good look immediately, but the slimy blob definitely seemed bigger than the first. When I lifted her leg to make sure she was getting the membrane off it's face, I realised it was actually 2 pups in the same sack, one laying on top of the other, both head first. They were identical, both cream, both females and even both exactly the same weight, at 174g each, whereas the first pup only weighed 145g also a female, but pure white".Mandy 12- 9- 2015
"Add me to your list! I had three sets where two pups attached to each other via a Y umbilical cord in one litter [of Alaskan Malamutes]. I have never seen that before or since. I was told by Cornell that it is a very rare occurrence and was due to the uterine environment and that I most likely will never see it again." 6-9-2016 

The original post is below:

Can dogs be identical twins, meaning two animals developed from the same fertilized egg, having the same genetic material and delivered in a single amniotic sac? The answer is somewhere between not likely and probably never.
That's just your reflection Bud, not your twin.
Puppies in a litter are usually fraternal twins or triplets and so on, no closer than you and your siblings, having the same mom and dad.

They can also be half sibs meaning they have the same mom, but different dads.


But monozygotic twins? The only foolproof way to identify identical twins is to use a DNA test, and no reports exist. Sometimes breeders report two pups in one placenta, but more likely the placentas grew together during the pregnancy.

Identical twinning in cats is
 fairly common.
What about pups with identical markings?  Random cell divisions that occur after the fertilized egg splits determine spot placement, along with where the fetus develops in the womb.  So two pups may look the same, but that doesn't mean they are identical.
Are these Aussie twin pups? Not likely.

Twin cows aren't unusual


Baby armadillos are  identical quadruplets.
Identical twins are fairly common in sheep cattle, cats, ferrets, deer, and humans, but identical twinning in dog just doesn't happen.


Just a band of brothers (and sisters)

11 comments:

  1. Very interesting post!!! This is not something I'd given a lot of thought to - love the photo of the mother with all her puppies, amazing how that can happen - two different fathers!

    ReplyDelete
  2. I have identical twin puppy's doberman to be exact I would like to learn more about this rare birth.

    ReplyDelete
  3. I have to say that until it happened to my dog, I never knew it could happen. 2 puppies, one sac with umbilical cord going from puppy to puppy and a 3rd cord going to mom. It looked like a Y or T. I just buried the babies as they did not survive. I could seal them up and send them to you if you wanted to see this yourself. Shocked the heck out of me - a seasoned and experienced breeder. My vet says this does happen just not very often

    ReplyDelete
    Replies
    1. This makes me wonder if twinning does in fact happen but the pups fail to thrive. Did they live for an extended period of time?

      Delete
  4. My dog had a litter of 15 on 11/12/15. She had a set of twins at 7:57am. 2 pups, one male on female, come out the same sac attached to the same plecenta. So yes, it is possible! I couldn't get a picture as the mother quickly tended to them. The female twin is very tiny about a third her twin brothers size but she is doing well and is definitely a fighter.

    ReplyDelete
    Replies
    1. Wouldn't this be a case of some type of placental fusing? Identical twins are never opposite sexes! This actually then brings into question if the other cases mentioned are actual identical twins or a repeat of this phenomenon.

      Delete
    2. That's impossible. If they were identical twins in the same sac, they would have to be the same sex.

      Delete
    3. One male and one female means they weren't identical, just merged placentas

      Delete
  5. My dog just had identical twin girls, she had a couple of hours after birth of first pup, then delivery of second was much more of a struggle. When it finally came out she got straight in and began cleaning the sack away so I never got a good look immediately, but the slimy blob definately seemed bigger than the first. When I lifted her leg to make sure she was getting the membrane off it's face, I realised it was actually 2 pups in the same sack, one laying on top of the other, both head first. They were identical, both cream, both females and even both exactly the same weight, at 174g each, whereas the first pup only weighed 145g also a female, but pure white.

    ReplyDelete
  6. Add me to your list! I had 3 sets where 2 pups attached to each other via a Y umbilical cord in one litter. I have never seen that before or since. I was told by Cornell that it is a very rare occurrence and was due to the uterine environment and that I most likely will never see it again.

    ReplyDelete
    Replies
    1. Wow! Very interesting. I added your comment above.

      Delete