Water on the Brain in Cats

Water on the brain in cats, also called hydrocephalus, is a bit of a misnomer as it isn’t water which causes the condition, but a buildup of cerebrospinal fluid (CSF). In a normal cat, CSF is constantly circulating throughout the brain area after being produced in the spinal area, and then eliminated through normal bodily processes. In a cat suffering from water on the brain, visible or symptomatic abnormalities are seen in the head area due to either a deterioration of the tissues in the brain which causes the appearance of larger amounts of fluid (compensatory hydrocephalus) or an inability or reduced ability for the fluid to properly drain (obstructive hydrocephalus). 

Some cats may not show any signs of water on the brain until the condition has become advanced, or the signs may be very subtle and difficult for the owner to recognize. Here are some of the signs you should watch for if you suspect your cat is suffering from hydrocephalus.

• Domed, irregularly shaped head, indicating fluid retention
• Seizures
• Behavioral problems
• Irregular sleeping habits
• Slow growth
• High stepping
• Difficulty eating, drinking or swallowing
• Coordination issues

Water on the brain in cats can be an inherited, congenital disease such as is often seen in certain cat breeds like the Siamese. It can also be an acquired condition from various infections or other causes.

Compensatory Hydrocephalus

Missing, necrotized or otherwise damaged portion of the brain that fills with CSF. A congenital defect or feline panleukopenia virus (FPV) may be the cause of damage and void in the brain cavity.

Obstructive Hydrocephalus

• Obstruction along the circulatory path of CSF
• Obstruction at point in brain where CSF is reabsorbed

Obstructions may be caused by a variety of conditions. In congenital cases, traumatic events to the mother while in utero or certain types of infections or medications given to a pregnant mother may result in cysts or tumors, causing hydrocephalus. Traumatic brain injury, cysts of unknown origin, tumors, inflammation, and hemorrhage are also causes of hydrocephalus acquired later in life.

As with many serious medical conditions, it will be vital that you provide a complete medical and symptom history to your veterinarian in order for proper diagnosis. You vet will be most interested in changes in appearance of the head and eye area, any recent trauma your cat may have incurred and any behavioral changes or symptoms. It’s also important to provide any information you may have regarding pedigree, birth or treatment of your cat’s mother during her pregnancy.

Your vet will want to conduct a thorough exam and a complete blood work panel to begin their diagnosis of this serious condition. Imaging of the head and neck will also most likely be ordered in order to help determine which form of hydrocephalus your cat is suffering from, which will affect the treatment options. Your vet may also order a spinal tap to analyze the CSF fluid being produced. Many of these diagnostic tests will require that your cat undergo anesthesia for the procedure.

Medications

Depending on the underlying cause and severity of water on the brain syndrome in your cat, your vet may decide the most appropriate line of treatment will be medications. Certain medications such as acetazolamide or methazolamide, decrease the production of CSF in the brain, which may allow proper drainage despite any obstruction or may reduce the amount of fluid in the case of the compensatory version of the condition. Diuretics may help reduce the amount of fluid in the brain, and in some cases steroidal drugs such as prednisone have been known to help. 

It is likely that your vet will prescribe some combinations of these drugs. If the underlying cause of your cat’s condition is permanent, then your cat will need regular medication throughout the course of its life in order to alleviate their neurological and physical symptoms. In the case of an injury or hemorrhage, reduction of fluid can encourage healing of area and medication may be slowly weaned off under the strict supervision of your veterinarian. 

Surgery

In severe cases, your veterinarian may prescribe a shunt to be placed in your cat’s head which will allow the excess fluid to drain. The purpose of a shunt is to alleviate the pressure caused by the fluid, which will then alleviate neurological symptoms in your cat. 

Surgery is not without complications. There is a possibility of infection, blockage or movement of the shunt. Regular visits to your veterinarian and compliance with all medication protocols, will help minimize the risks of these complications. 

Palliative Care

It’s an unfortunate reality that in some severe cases of water on the brain in cats, the best care will be that which alleviates pain and discomfort for your cat. Your veterinarian will be able to discuss the chances of recovery through either medication or surgery and can assist you with quality of life concerns to determine whether there is an effective treatment option available. 

In mild to moderate cases of water on the brain in cats, such as when an injury has caused the condition, prognosis for recovery with appropriate medication is very good. If medication is needed throughout your cat’s life, regular vet visits will be required in order to ensure appropriate dosage of medication and to confirm the hydrocephalus is not progressing. Your vet may also run occasional bloodwork to determine the long term medication is not damaging any other internal organs.

With severe cases requiring a medical shunt, surgery often relieves some, but not all of the neurological symptoms. As the pressure from fluid buildup is relieved from the brain, some healing can occur. It will be important to work with your veterinarian to develop a rehabilitative course of action.