WHAT IS A BRAIN TUMOR?
Strictly speaking, the term brain tumor simply means a mass in the brain. However, it is commonly used to describe a cancerous (or neoplastic) mass inside the cranial cavity. Brain tumors may be primary, arising from the cells of the brain and its lining, or secondary, arising elsewhere and spreading to the brain.
PRIMARY BRAIN TUMORS
Primary brain tumors seen in dogs and cats include meningioma, glioma, choroid plexus papilloma, pituitary adenoma or adenocarcinoma, and others.
Meningioma – This is the most common primary brain tumor in dogs and cats. It arises from the arachnoid mater of the meninges (the membranes that line the brain) rather than the cells of the brain itself. As such, meningiomas are not strictly brain tumors, but tend to be grouped with them because they arise within the cranial cavity and compress or invade the brain. These tumors occur more commonly in long nosed breeds of dog, such as Golden Retrievers. Meningiomas are usually relatively slow growing and amenable to treatment, although more malignant forms do occur.
SECONDARY BRAIN TUMORS
Secondary tumors represent spread (metastasis) of another tumor to the brain from elsewhere in the body. Examples of tumors that may spread to the brain include hemangiosarcoma, mammary carcinoma and melanoma. These tumors carry a very poor prognosis because they have already spread through the body. It is routine practice to take radiographs of the chest cavity and to ultrasound the abdomen to check if there is any evidence of cancer elsewhere in the body whenever a diagnosis of a brain tumor has been made or is suspected.
WHAT ARE THE SIGNS OF A BRAIN TUMOR
Brain tumors cause signs by compressing or invading the brain. The resulting signs related directly to the area of the brain affected and are not specific to a tumor: any disease affecting that area of the brain could produce similar signs. As a general rule, brain tumors cause progressive signs in older animals. Signs may start very suddenly or appear gradually. Signs may also wax and wane in severity.
SIGNS OF A BRAIN TUMOR IN THE FOREBRAIN
- Behavioral Abnormalities Such As Loss of Learned Behavior and Depression
- Increased / Decreased Appetite & Thirst
- Constant Pacing or Circling
- Decreased Awareness and Vision on One Side of the Body
- Behave As If In Pain
SIGNS OF A BRAIN TUMOR IN THE BRAIN STEM
- Head Tilt
- Leaning / Falling to the Side of the Head Tilt
- Loss of Balance
- Involuntary Flicking of the Eyes
- Loss of Appetite & Vomiting
- Abnormal Eye Position
SIGNS OF A BRAIN TUMOR IN THE CEREBELLUM
- Uncoordinated Gait
- Head Tremors
- Wide Based Stance
HOW IS A BRAIN TUMOR DIAGNOSED
A brain tumor should be suspected whenever there is a new onset of neurological signs in an animal older than 5 years. It is important to understand, that with rare exceptions, brain tumors are tumors of the soft tissues of the brain and they cannot be seen on radiographs of the skull. Allure Integrated Pet Specialists Neurology Department utilizes a multi-step approach to diagnose brain tumors.
- Comprehensive Patient History
- Complete Physical and Neurological Exam
- Routine Blood Work
- Thoracic Radiographs
- Magnetic Resonance Image (MRI)
HOW ARE BRAIN TUMORS TREATED
Options for treating brain tumors include surgical removal, radiation therapy, chemotherapy, and palliative treatment of the symptoms. Unfortunately, we have relatively little data to present on the outcome of tumors because it is common for owners to decide not to treat their pet, or because pets are treated with radiation therapy or chemotherapy without ever determining the tumor type.
Allure Integrated Pet Specialists Neurology Department will go over your pet’s individual treatment options during your consultation.