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Hydrocephalus in Dogs

Hydrocephalus is fluid on the brain in dogs.

Hydrocephalus is a serious condition in dogs during which cerebrospinal fluid (CSF) doesn't drain properly and, instead, builds up inside the skull and puts abnormal pressure on the brain. It is also sometimes called fluid on the brain.

What Causes Hydrocephalus in Dogs?

There are two types of canine hydrocephalus: compensatory and obstructive.

  • Compensatory hydrocephalus occurs when CSF fills a space that should have healthy tissue in it. Either that tissue was destroyed by another condition, or it never developed properly.
  • Obstructive hydrocephalus occurs when something is blocking the normal CSF circulation. As a result, CSF builds up in the skull and intracranial pressure increases.

Obstructive hydrocephalus is further broken down into two categories:

  • Congenital: An abnormality of the structure of the brain, usually caused by a prenatal infection, causes the obstruction.
  • Acquired: Obstruction is caused by a tumor, abscess, or inflammation in the brain.

In rare circumstances, hydrocephalus can be caused by overproduction of CSF rather than impairment of its ability to drain.

Congenital hydrocephalus in dogs is most common in small breeds like Chihuahuas, Maltese, Pomeranians, toy poodles, Yorkies, Lhasa apsos, and Boston terriers.

Signs of Hydrocephalus in Dogs

Signs of hydrocephalus in dogs may be vague or, in the case of acquired conditions, more related to the underlying cause. Some signs that may be seen include:

  • Difficulty training
  • Sleepiness
  • Hyperexcitability
  • Enlarged area on the head or dome-shaped forehead
  • Abnormal behavior
  • Blindness
  • Incoordination
  • Seizures

Diagnosis of Hydrocephalus in Dogs

Skull x-rays, CT scan, and MRI can all show abnormalities of the skull and excess fluid inside of it.

Treatment of Hydrocephalus in Dogs

Patients with mild signs may be treated with corticosteroids (usually prednisone) to lower CSF production, mannitol (an osmotic diuretic) to decrease the CSF fluid and reduce intracranial pressure, and treatment of the underlying cause in acquired cases.

Surgery to shunt the CSF from the skull to the abdomen is the definitive long-term treatment. Side effects can include infection and blockage of the shunt.

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