MidnightBlue Chihuahua's of Walkerton,Indiana

                                                                            

There is an opening in the skull of a Chihuahua, a hole, a molera. This opening is in the center of the Chihuahua's forehead.  The molera can be very tiny to very large.  The edges of the molera can be round and smooth or even jagged.  The molera was once considered to be a "mark of being purebred."  However, there are many Chihuahuas that have been well bred and they have little or no molera!

There is only one molera on a Chihuahua because if there is more than one molera this isn't normal.

The Chihuahua's molera or fontanel, is considered a breed characteristic and not a defect.  Most Chihuahuas have a molera- a soft spot on the top of their head which is similar to the soft spot that human babies are born with.  There are many Chihuahuas that are born without the molera but there are just as many Chihuahuas born with one and its presence is nothing to be alarmed over.  Most moleras in Chihuahuas do shrink as they mature but it doesn't always close completely.  It can be between a nickel and dime size but the molera can vary in shape and size. The molera shouldn't be any larger than the size of your thumb print, and there shouldn't be any swelling, bulging or throbbing. The molera isn't going to be a problem as long as you are gentle when petting and handling your Chihuahua's head.

It is very unfortunate, that there are many lay people and some uneducated Veterinarians that are not familiar with the Chihuahua breed and they have tried to link the very presense of a molera with conditon known as hydrocephalus ~ "water head" or water on the brain. There is also a term of open fontanel. (Open fontanels allow the skull to give during the birth to some degree so the puppy can pass through the birth canal. Generally this opening quickly closes up and calcify to make a strong skull.) This has caused many people who aren't familiar with the Chihuahua breed and the molera, serious concern and undo worry.  The truth is that a domed head with a molera present doesn't predispose the Chihuahua to this condition. 

Hydrocephalus

A puppy can be born with hydrocephalus or a brain injury can cause water on ther brain.  Hydrocephalus is caused by an excessive accumulation of cerebrospinal fluid in the ventricles of the brain.  This compresses the brain against the skull and it may not be noticed until the puppy is several months old.  Generally when you see a puppy with water on the brain you will be able to tell immediately that there is something wrong with them.

Signs of Hydrocephalus ~ Water on the Brain

1.  Wide-set or protruding eyeballs (a lot of white showing at the corners)

2.  Blindness

3.  Abnormal behavior

4.  Walking in circles

5.  Slowness both mentally and physically

6.  Seizures

7.  Abnormally slow growth

8.  Lack of coordination

9.  Easty ~ Westy eyes.  In other words, one eye can go to the west and the other to the east.

There is no cure for water on the brain.  Mild cases can be treated with sterods and diuretics to reduce pressure, or with surgically inserted shut to divert fluid from the brain to the abodomen.

Having an x-ray isn't a good indication of hydrocephalus.  It is better to have a ultra sound or have a MRI done to determine for sure that your Chihuahua has water on the brain. This would make a definite determination of hydrocephalus.

Head
A well rounded "apple dome" skull, with or without molera.  This is according to AKC.

http://www.akc.org/breeds/chihuahua/