Hydrocephalus
Race Foster, DVM
Marty Smith, DVM

Hydrocephalus can occur as a congenital condition as well as a result of trauma or a brain tumor, for instance. Hydrocephalus is a condition in which excessive fluid is found within and around the brain. The body may form too much fluid or, as occurs in most cases, the fluid that is produced cannot drain from the central nervous system as it normally does. Within the brain are fluid-filled spaces called ventricles. In a hydrocephalic dog, the ventricles fill with too much fluid. They become swollen, and the increased pressure damages and/or prevents development of brain tissue. Toy breeds such as Maltese, Yorkshire Terriers, Pomeranians and Chihuahuas are commonly affected. Hydrocephalus occurs in other breeds as well.

What are the Symptoms?
Typically, hydrocephalus is first diagnosed when the dog is young, usually less than four months of age. The head takes on a dome-shaped appearance and the skull bones at the top of the head fail to close. A soft spot may be noticed on the top of the head. This is termed an 'open fontanel.' The affected dog may be blind, have seizures or have an altered gait. Hydrocephalic dogs are commonly mentally dull and have a limited ability to learn. Different levels of severity exist.

What are the Risks?
The hydrocephalic dog typically has a very limited life span. Severity differs, but few dogs with this condition live to be over two years of age.

What is the Management?
Most cases go untreated. Veterinary neurologists can be consulted and occasionally the excess fluid can be drained. Sometimes lifelong treatment with prednisone and Lasix is tried. With surgery or medical treatment, however, the dog will rarely live a normal life. Treatment is often unsuccessful and expensive. Hydrocephalus is a congenital disease and dogs with this condition should be removed from any breeding program.

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