Brain Tumors

Posted on July 3, 2015

Brain tumors are diagnosed in pets older than 5 years and mainly over 9.  Brain tumors are common, and even young animals can be affected.  Certain breeds are more predisposed, such as Boxers, Golden Retrievers, and male short-hair domestic cats.  The most common brain tumors in dogs are meningiomas and gliomas, while cats suffer meningiomas.

Meningiomas envelope the brain meninges and can be accessible for surgical removal, especially in cats. Gliomas are generally located deeper in the brain, making surgical removal more difficult.

The tumors that originate in the brain cavity are called primary brain tumors, and those that orginate from outside the brain are called secondary brain tumors.

Symptoms of a brain tumor depend on location and size of the tumor.

Not all dogs experience symptoms, as other diseases can cause similar symptoms.  Symptoms can develop over time, or more slowly.

1.       Seizures- Present in half of the cases

2.       Circling

3.       Confusion

4.       Tilting head

5.       Behavioral changes

6.       Loss of balance

Dogs younger than 5 with seizures are more likely to suffer epilepsy, as older dogs more likely suffer a brain tumor.  Depending on growth rate, a brain tumor can cause bleeding, swelling and compression issues in the brain.

Cats generally suffer changes in behavior.

Diagnosis of a brain tumor is generally done with a brain scan or imaging.

Imaging of the brain with a CT-scan or magnetic resonance imaging (MRI) is used to diagnose a brain tumor without pain in a noninvasive manner.  A CT-scan divides the brain into slices using x-rays, while the MRI uses a magnetic field to produce an image of the brain. Generally the procedures are performed with anesthesia to keep the pet completely still.  Blood tests and other diagnostic procedures help ensure a pet can tolerate anesthesia and rule out other disease causes.  A spinal tap can rule out additional causes for a brain tumor.  A needle biopsy during the CT-scan may be used to help determine the tumor type.  The tumor’s appearance may be diagnosed from the CT-scan or MRI alone.

Treatment of a brain tumor can include the following

1.        Anti-epileptic drugs to control seizures

2.       Steroids to reduce swelling

3.       Surgery for excision

4.       Radiation therapy

5.       Chemotherapy

Radiation and chemotherapy can be recommended for hard to reach tumors in the brain.

Life expectancy for pets diagnosed with a brain tumor can be difficult to answer, as survival times are dependent on many factors.  However, averages have been calculated.

1.       Surgical and radiation animals have a median survival time of 10 to 14 months.

2.       Cats with meningioma can last 2 years and sometimes longer.

3.       50% of patients will live longer.

4.       Survival time is usually a few weeks to months with supportive therapy only.