The presence of a molera in a Chihuahua DOES NOT make the dog any
more or less susceptible to brain injury, seizures or hydrocephalus.
The molera should not usually be any larger than
the size of your thumb print, and there should be no swelling, bulging or throbbing. Check carefully on the sides of the head
for normal bone there as well; make sure there is no more then one molera, on the top of the head only, as more than a single
molera is not normal.
Hydrocephalus is the accumulation of excess cerebrospinal fluid in the brain and is not normal
for any breed, nor is it curable. Hydrocephalus is also known as "water on the brain" or "hydro". When fluid accumulates in
the brain, it compresses the brain against the skull. A puppy can be born with this disorder, or it can be caused by a brain
infection or head injury later in life. Chihuahuas born with "hydro" do not generally live more than a few months, and they
do not grow normally, often staying extremely tiny.
Signs of hydro include wide-set or protruding eyeballs (often
with a lot of "white" showing at the corners), blindness, abnormal behavior, walking in circles, slowness (mental and physical),
seizures, abnormally slow growth and lack of coordination.
Concerns about Chihuahua moleras and/or hydro should be
addressed to a licensed veterinarian. Be aware, however, that many veterinarians not familiar with Chihuahuas have WRONGLY
told owners that their puppy is unhealthy and/or hydrocephalic just because of the presence of a normal molera. Diagnosis
is based on the signs in conjunction with techniques to image the brain. In dogs with a molera, ultrasound can be performed
by scanning through the molera to detect the excessive accumulation of fluid within the brain.
is no cure for hydrocephalus. Mild cases can be treated with steroids and diuretics to reduce pressure, or with a surgically
inserted shunt to divert fluid from the brain to the abdomen