A meningioma is the most common type of brain tumor in dogs. This type of tumor arises from the meninges, a protective lining that surrounds the brain and the spinal cord. Breeds such as the German shepherd and collies are more prone to these tumors.
Dogs that are more than 8 years of age are also more likely to develop meningiomas and both sexes show an equal predisposition for this type of brain tumor.
Meningioma in Pets
A meningioma is generally a benign tumor that remains confined to one area and doesn’t spread. However, some meningiomas can be malignant. The brain and cerebrospinal fluid occupy the skull and there is little extra space left over. As a meningioma forms and grows, it compresses the brain resulting in inflammation which in turn results in more swelling causing damage to nerves of the brain.
A meningioma grows from the skull inwards and most meningiomas occur in the front of the skull where the olfactory lobes are located. Benign meningiomas develop slowly and are non-invasive whereas malignant ones develop rapidly.
Symptoms of Meningioma
Meningioma symptoms include:
- Weakness in the limbs
- Uncoordinated walking
- Personality changes
- Changes in appetite
- Blindness
- Walking in circles
- Disorientation
- Depression
- Difficulty in swallowing
- Vomiting
- Seizures
- Lameness on one side of the body
- Facial paralysis
- Dragging of toes
- Tilting the head to one side
- Tremors
- Loss of balance
Causes of Canine Meningioma
There is no known cause of meningioma in dogs. However, exposure to radiation, especially in the facial area, can increase the risk of developing meningiomas. Certain hormones can also increase the rate of growth of a meningioma.
Diagnosis of Meningioma in Dogs
In addition to evaluating the pet’s medical history and performing a physical exam, the vet will perform a complete blood count test, a urinalysis, X-rays of the chest, CT scan and MRI.
Treatment of Meningioma in Dogs
Treatment depends on the location and size of the tumor, the pet’s age and his fitness level. Medicines to control the epilepsy and steroids to control the edema are often necessary. A meningioma is generally treated with surgery, chemotherapy and radiation. Surgery is often performed to remove the tumor.
Radiation Therapy for Dogs
Radiation therapy involves the use of high powered rays to damage cancer cells and prevent them from growing. Post surgery, radiation therapy is used to discourage the development of new tumors. Radiation therapy is also used in cases where surgery is not an option. Your pet has to be anaesthetized if the treatment involves surgery and radiation therapy.
Chemotherapy involves the use of drugs to kill cancer cells. These drugs should be able to cross the blood-brain barrier in order to be effective against a meningioma. However, there are very few drugs that can cross the blood-brain barrier and can be used to treat a meningioma.
Untreated dogs have a life expectancy of 2 months. Prognosis is improved with treatment, proper nutrition and supportive care. Such pets survive for a year or more.