This shows the position where the molera is located.
Most chihuahuas are born with a soft spot in the top of their head, very similar to that of a human baby. This is because the chihuahua's head is so large that it is difficult to pass through the birth canal. This soft spot is perfectly normal and, in fact, was once considered to be a must have trait to be a purebred dog. Almost all breed standards still mention the molera.
Most moleras are closed by the time that the dog reaches one year of age, although it may take up to three years to close. Very few Chihuahuas have moleras that remain largely open after three years of age. A large molera is considered to be larger than a thumbprint.
Extra care must be taken with pups that retain a large molera when playing or running, especially around other pets, small children and people, as even a light blow to the head could be fatal.
If we sell a pup that we feel still has a large molera, we will make the buyers sign the Molera Warning contract, just to show that we have informed them of this condition.