An Irish shepherd gave birth to identical twin puppies. Actually, these are the first identical puppies which are known to science.
Such cases were previously reported with horses and pigs, but are extremely rare in most animal species.
This represents a rare example of monozygotic or identical twins in mammals.
The vet suspected that these are identical twins after he gave birth of the same placenta by Cesarean section.
He noticed that they have same class and have very similar patterns, then his suspicions were confirmed with a blood test.
“DNA samples of twins are identical in all 40 genetic markers,” the researchers said, making them the first monozygotic dog twins, confirmed through DNA profiling.
Twins can be monozygotic (or identical). This means that they develop the same zygote (or egg cell) which is impregnated from the same sperm.
Or dizygotic, meaning that they develop from two different eggs, fertilized by different sperm.
Just like in humans and in animals, identical twins can have small subtle differences in height, in a scar or mole, and the like, because the genes that encode certain physical differences may be expressed in different ways.
So these puppies, although identical twins, have slightly different markings on paws, tail tip and chest.