Just like human babies have fontanels, Chihuahuas have a soft spot, otherwise known as a Molera. The Molera is located on the top of the skull and can vary in size and shape. It should be no larger than a thumb print. The Molera may fill in with age, but some may not close completely, therefore always ensure there is great care taken to prevent head injury. Never press or place any pressure on the Molera as this could cause brain injury. Many veterinarians are not familiar with the Chihuahua as a breed and mistakenly confuse a Molera with a serious condition called Hydrocephalus (water on the brain). Please note the Chihuahua's Molera is not a defect, it is a breed characteristic.