The Chihuahua Molera

Many Chihuahuas are born with an opening (or soft spot) at the top of their skull. This opening is known as the Chihuahua Molera (or fontanel). While this is very similar to a human baby's soft spot, it is unlikely most Chihuahuas will outgrow it.

The Chihuahua's molera (or fontanel) is considered a breed characteristic and not a defect. Unfortunately some veterinarians not familiar with the Chihuahua Breed may diagnose the molera incorrectly as Hydrocephalus (water on the brain).

The molera usually shrinks as the dog matures and ends up between nickel- and dime-sized. In rare cases, it can remain quite large and can be a sign of Hydrocephalus; but, Hydrocephalus has several other signs besides a larger than usual molera.


As shown in the illustration below, the molera in a Chihuahua will be on the top of the head and may vary in shape and/or size when there is a molera present.