Okay, I found some info, but it's a bit lengthy. Hope it helps!
1. I also have a chi with Hydrocephalus. He is about 19 months old now. He had his first seizure at 5 months (that we noticed). We currently have him on a steroid prescribed by our vet. He still shows signs of Hypermetria (awkward gait). It almost looks like he marches when he walks. He plays well, only his agility and coordination isn't near what it should be. Will your pup die? Definitely, if untreated. You may be able to make his/her life much more meaningful with the right treatment. Since we have had our dog on steroids, he hasn't had any more seizures. Steroids help reduce the production of CSF that causes the pressure on his brain. The pressure is what causes the seizures. The prescription costs us about $15 for a one-month supply. This may differ for your dog. Hope this helps! We hope our dogs stays around for a while and it looks good so far!
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 thier 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.
Unfortunately, there 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.
A dog with hydrocephalus (a.k.a. water on the brain) may have an unusually large head for his size caused by swelling. Other signs of this fatal condition are frequent falling, seizures, a lot of white showing in the eyes, an unsteady gait, and east-west eyes (the opposite of crossed eyes). A dog with hydrocephalus is in pain and won't live long, so euthanasia is the humane solution. (Euthanasia is the medical term for a humane, vet-assisted death.)
What is hydrocephalus?
With hydrocephalus there is an abnormal build-up of cerebrospinal fluid (CSF) in cavities ( the ventricles) in the brain. The resulting increased pressure on the brain causes the clinical signs that occur with this condition.
Hydrocephalus can be primary (congenital ) - the animal is born with the condition, or secondary - the condition is acquired later in life due to some disease process that blocks normal drainage of the CSF. The primary form, discussed here, is seen most often in brachycephalic (dogs with a shortened head) and toy breeds.
How is hydrocephalus inherited?
The mode of inheritance is unknown, but there is a predisposition to this condition in the breeds listed below.
What breeds are affected by hydrocephalus?
Toy breeds - Cairn terrier, chihuahua, Maltese, Manchester terrier, pomeranian, toy poodle, Yorkshire terrier - and brachycephalic breeds - Boston terrier, English bulldog, Lhasa apso, Pekingese, Shih tzu
For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.
What does hydrocephalus mean to your dog & you?
Puppies with severe hydrocephalus often die at a very early age due to pressure from the increased fluid in the brain. In other less severely affected pups, the signs gradually become apparent over the first few months of life, and in some mild cases the condition is only diagnosed later in life.
The types of signs seen with this condition include unthriftiness (smaller than littermates, slow to grow), a domed skull (which gradually becomes more pronounced), abnormal movement behaviours (restlessness, aimless walking), problems with vision, and seizures. These pups are very slow to learn - it may be extremely difficult to housetrain them for example.
Generally the signs gradually worsen, although by 2 years of age they may stabilize. To minimize brain damage, the condition must be recognized and appropriate treatment begun early. However, affected animals will likely always be slow and have a limited ability to learn.
How is hydrocephalus diagnosed?
Hydrocephalus can be difficult to diagnose. Your veterinarian will consider the combination of physical, behavioural and neurological abnormalities in your dog. The diagnosis can be confirmed by MRI or CT scanning, or by ultrasonography in some cases.
For the veterinarian: Ultrasonography can be performed through an open fontanelle to confirm ventricular enlargement. An open fontanelle is not diagnostic per se of hydrocephalus, as it may occur in a normal healthy dog.
Some hydrocephalic dogs have a bilateral divergent strabismus ("setting sun sign").
How is hydrocephalus treated?
Corticosteroids are used, and then gradually tapered off, with the aim of lowering the amount of cerebrospinal fluid in the brain. Your veterinarian may also prescribe short-term diuretics with the same goal. Treatment often needs to be repeated, although some dogs will stabilize by about 2 years of age. Affected dogs are susceptible to other medical problems and may have a poor tolerance to various drugs.
Phenobarbital may be required in dogs that experience seizures.
A sophisticated procedure that may be of some benefit in severe cases of hydrocephalus is surgical placement of a permanent shunt to drain the fluid. Your veterinarian will refer you to a specialist if you wish to to consider this option.
Depending on the severity of the clinical signs, and recognizing the ongoing medical problems these dogs may face, your veterinarian will likely discuss with you humane euthanasia as another option for your pup.
Affected animals should not be bred. Even though little is known about the heritability of this condition, it is also preferable to avoid breeding dogs who are unaffected but have a familial history of hydrocephalus.
FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN
Whoever said money can\'t buy happiness, forgot little puppies!