Overview
Hydrocephalus is a condition where extra fluid, called cerebrospinal fluid (CSF), builds up inside the skull. Normally, CSF surrounds and cushions the brain and spinal cord, but when too much fluid collects, it can cause the spaces inside the brain to enlarge. Because the brain sits inside a fixed, enclosed space, this buildup can create pressure that may lead to neurological problems.
Causes
There are two main types of hydrocephalus in pets:
- Congenital hydrocephalus – This form is caused by a narrowing of a small channel in the brain called the mesencephalic aqueduct, which normally allows CSF to flow to the spinal cord. It is present from birth and is seen most often in small or toy breed dogs, such as Chihuahuas, Yorkies, and Maltese. Pets with congenital hydrocephalus often begin to show signs between 6 and 12 months of age, but some pets don’t show signs until much later or may be asymptomatic.
- Acquired hydrocephalus – This type develops later in life and happens when something blocks the normal flow of CSF. Causes may include tumors, infections, inflammation or structural abnormalities, such as Chiari-like malformation.
In both types, the blockage or narrowing causes fluid to build up, which can put pressure on the brain and lead to neurological signs.
Clinical Signs
The clinical signs of hydrocephalus can vary widely, from pets showing no obvious symptoms to those who are severely affected. Common signs of pets who are affected include dullness, difficulty learning basic commands, and sometimes changes in behavior. In more advanced cases, seizures and problems with walking may also occur.
Pets with hydrocephalus often have a characteristic dome-shaped head, a soft spot on the skull that remains open, and eyes that appear to look downward and to the side.
Diagnosis
To diagnose hydrocephalus, an MRI scan is needed. This imaging allows us to assess how severely the brain’s fluid-filled spaces are enlarged and to detect any changes in the surrounding brain tissue. It also allows us to rule out other possible causes for your pet’s symptoms.
Treatment
Treatment for hydrocephalus usually involves either medication or surgery.
- Medical management – Medications aimed to reduce the production of the extra fluid in the brain to help lower the pressure inside the skull. Medications like prednisone and omeprazole have been shown to help with this. If your pet is having seizures, we may also prescribe anticonvulsants
- Surgical Management – If medications aren’t enough or if the condition is more severe, surgery may be recommended. The most common procedure is called a ventriculoperitoneal shunt. This involves placing a small tube that helps drain the excess fluid from the brain into the abdomen, where the body can safely absorb it. This surgery improves symptoms in the majority of patients, but comes with some risks, such as infection or blockage of the shunt, and often may require additional revision surgeries later on in life.
Prognosis
The prognosis for hydrocephalus in dogs can vary quite a bit depending on several factors, including the severity of the condition and whether it is congenital or acquired. In mild to moderate cases managed early with medication often have a fair to good prognosis, meaning many dogs can live a comfortable life with proper treatment and monitoring. In severe cases or those that don’t respond well to medical management may have a more guarded prognosis.
Overall, with appropriate treatment, many dogs can have a good quality of life for years. Regular follow-ups and adjustments to treatment are often required.