Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) builds up in the cavities of the brain. This causes an increase in intracranial pressure which leads to the clinical symptoms of the disorder. The causes of hydrocephalus are unclear but there does appear to be a hereditary component. Hydrocephalus is most commonly seen in toy breeds of dogs such as terriers, Chihuahuas, and Pomeranians as well as certain brachycephalic breeds such as the bulldog or Lhasa apso. This condition is always present from birth and many puppies with hydrocephalus die long before adulthood. An animal with hydrocephalus should not be bred because they are more likely to have puppies with the condition.
Symptoms and Diagnosis
Pets with hydrocephalus will demonstrate a number of symptoms that are related to the intracranial pressure that builds up in affected animals. As mentioned earlier, many infant animals with hydrocephalus will die but there are less severe symptoms. In animals with a less serious case of hydrocephalus, symptoms will reveal themselves gradually over the first few months of life. In very mild cases of hydrocephalus, diagnosis may not be made until adulthood.
Typical signs of hydrocephalus include a misshapen (dome-shaped) skull, abnormal behaviour such as restlessness or aimless walking, problems with vision, seizures, and developmental disability. Dogs with hydrocephalus tend to learn more slowly making them quite difficult to train. House training is a particularly difficult issue for animals suffering from hydrocephalus. In addition, hydrocephalic animals are often much smaller than their littermates and their physical growth is slow. In most cases the symptoms of hydrocephalus will worsen over the first 2 years of life by which point the severity of these symptoms becomes more stable. In order to minimize the symptoms of hydrocephalus it is important to seek early diagnosis and treatment. Though this condition will affect them for life and developmental and physical disabilities usually cannot be avoided, many animals can be treated and lead moderately healthy lives.
Diagnosing hydrocephalus can be very difficult. They symptomology of the disease is not vey specific meaning the signs of the disorder can be attributed to many other illnesses. Your veterinarian will have to conduct a very thorough physical and behaviour examination in order to recognize the neurological deficits your pet might be displaying. Usually an MRI, CT scan, or Ultrasound will be required in order to confirm diagnosis.
Treating hydrocephalus focuses on reducing the amount of intracranial pressure your pet is experiencing. Certain drugs, like corticosteroids, are often prescribed with this exact goal in mind. By reducing the amount of CSF in the brain, corticosteroids help to reduce intracranial pressure. Diuretics are also often utilized as they have similar effects. If your pet is experiencing seizures specific medication (i.e. Phenobarbital) is diagnosed in order to treat this symptom. There is also a surgical treatment that involves inserting a permanent shunt in the brain to drain CSF. This option is obviously more expensive, requires a specialist, and is usually only done in the most severe cases. Finally, some vets and pet owners will want to consider euthanasia in cases where the quality of life of your pet is severely impaired.