Hydrocephalus in Dogs

Prognosis depends on the underlying cause and the severity of the condition. Congenital hydrocephalus is not curable, but treatment options are available to help relieve the symptoms. Many dogs born with the condition are often able to live full lives with treatment. Congenital hydrocephalus is uncommon, but some breeds are more predisposed than others.

Hydrocephalus developing later in a dog’s life is associated with serious conditions developing inside the cranium, like a brain tumor. Acquired hydrocephalus can also be caused by intracranial bleeding or inflammatory brain disease. Adult dogs that show symptoms of hydrocephalus with no prior history of the condition need veterinarian attention immediately. Prognosis for acquired hydrocephalus depends on the underlying condition. Hydrocephalus due to a tumor carries a more guarded prognosis than an infection.

Hydrocephalus manifests differently depending on the severity of the condition. Some animals may be asymptomatic, while others have decreased cognitive abilities. Treatment can help relieve symptoms but the condition is often permanent, especially if the dog was born with it (congenital).

Congenital hydrocephalus is more prominent in toy breeds and brachycephalic breeds.

Dog breeds that tend towards naturally domed heads are most commonly affected:

• Chihuahua
• Yorkshire terriers
• Pug
• Pomeranian
• Toy poodle
• Shih Tzu
• Lhasa apso
• Pekingese
• English bulldog
• Boston terrier
• Maltese
• Cairn Terrier

One symptom, head pressing, where the dog presses their head to a wall or object for seemingly no apparent reason, is often a symptom of brain damage and is an emergency.

Hydrocephalus results from improper regulation of fluid inside the skull. Irregularities are caused by a dysfunction in too much fluid production, too little fluid absorption, or blockage of the fluid pathways. It is most often a congenital condition, where the dog is born with some anatomical abnormality that leads to the dysfunction.

Hydrocephalus can also be acquired during the dog’s life. Most often, a mass inside the head (like an abscess or brain tumor) obstructs the flow of fluid inside the skull. It can also be caused by intracranial bleeding from a head injury.

Symptoms vary depending on the underlying cause, the location of affected brain tissue, and the amount of fluid in the cranium. Some dogs are asymptomatic, and do not show any symptoms.

Hydrocephalus can be difficult to diagnose, as the physical symptoms, like the large domed head and eye abnormalities, can be caused by many different conditions.

Diagnostic imaging is the primary way to confirm hydrocephalus.

• MRI - most reliable
• CT scan
• Measuring electrical activity within the brain (EEG)
• Radiographs
• Ultrasound - an option in puppies before skull is fully ossified

Congenital hydrocephalus may be physically apparent at a young age but until the skull is fully ossified, added pressure on the brain may not be sufficient to lead to neurologic symptoms.

The goal of treatment is to relieve pressure on the brain. This can be done medically and surgically, and is often done in tandem.

Medical treatment works to reduce the amount of cerebral fluid produced. Careful monitoring is necessary during treatment because the dog can get dangerously dehydrated. Antibiotics are used when hydrocephalus occurs as a result of an infection. Surgical placement of a shunt redirects the excess fluid into a part of the body that can absorb it. Surgical shunts are used for both congenital and acquired hydrocephalus.Shunts relieve the pressure on the brain,and may need to be replaced as the animal grows. Dogs with acquired hydrocephalus may only need the shunts temporarily during treatment and recovery.

Obstruction caused from a mass in the cranium is more difficult to treat. Depending on the location and complexity of the mass, aggressive surgical treatment may not be a viable option. Chemotherapy and radiation therapy may be attempted.

Congenital hydrocephalus is a lifelong condition and the goal of treatment is relief of symptoms. Prognosis varies depending on the severity of the condition and how the dog responds to treatment.

Prognosis for acquired hydrocephalus also varies. If caused by an infection, treatment may relieve pressure on the brain and lead to recovery. An obstruction caused by a mass, like a brain tumor, carries a guarded prognosis even with aggressive treatment.

Quality of life is an important consideration during and after treatment. Permanent neurological deficits may occur.

For congenital hydrocephalus, selective breeding can help prevent the disease.

Hydrocephalus is not contagious. If caused by an infection, the infecting organism may be passed along to other pets in the home.

Hydrocephalus is uncommon, but some breeds are more prone than others.

The goal of treatment is to relieve pressure on the brain. This can be done medically and surgically, and is often done in tandem.

Medical treatment works to reduce the amount of cerebral fluid produced. Careful monitoring is necessary during treatment because the dog can get dangerously dehydrated. Antibiotics are used when hydrocephalus occurs as a result of an infection.Surgical placement of a shunt redirects the excess fluid into a part of the body that can absorb it. Surgical shunts are used for both congenital and acquired hydrocephalus. Shunts relieve the pressure on the brain, and may need to be replaced as the animal grows. Dogs with acquired hydrocephalus may only need the shunts temporarily during treatment and recovery.

Obstruction caused from a mass in the cranium is more difficult to treat. Depending on the location and complexity of the mass, aggressive surgical treatment may not be a viable option. Chemotherapy and radiation therapy may be attempted.