Brain Tumor (Astrocytoma) in Dogs

PetMD Editorial
May 18, 2010
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Astrocytoma in Dogs

  

Astrocytomas are brain tumors that affect the organ's glial cells, which surround nerve cells (neurons), giving them support and electrically insulating them. It is the most common primary neoplasm occurring the brain of dogs. However, an astrocytoma can also be rarely found in the spinal cord, and there was one reported case of an astrocytoma located in the retina.

Symptoms and Types

The astrocytoma's biologic behavior depends on the tumor's location and degree of lack of cell differentiation (graded I–IV, from best to worst prognosis). The following are some common symptoms associated with this type of brain tumor:

  • Seizures
  • Behavioral changes
  • Disorientation
  • Loss of conscious proprioception (i.e., clumsy misplacement of feet, tripping, etc.)
  • Cranial nerve abnormalities
  • Paralysis

Causes

The underlying cause for the development of astrocytomas is currently unknown.

Diagnosis

You will need to give a thorough history of your dog’s health, including the onset and nature of the symptoms, to the veterinarian. He or she will then perform a complete physical examination as well as a biochemistry profile, urinalysis, complete blood count, and electrolyte panel to rule out other diseases.

An analysis of cerebrospinal fluid may indicate increased protein levels without an increase in cell count, which is indicative of astrocytoma development. Computed tomography (CT) and magnetic resonance imaging (MRI) are also highly instrumental in diagnosing astrocytomas, as is radionuclide imaging, which may show an area of increased activity at the tumor site.

  

Treatment

Surgery and chemotherapy are both common courses of treatment when dealing with this time of brain tumor. Radiation therapy, too, can be effective; consult a veterinary oncologist if this is beneficial in the case of your dog.

Living and Management

Your veterinarian will schedule regular follow-up appointments for your pet, where it will undergo CT (computed tomography) and MRI (magnetic resonance imaging) scans, so as to monitor the dog's response to treatment. Likewise, blood work (especially a complete blood count) should be evaluated during each appointment. If the dog was prescribed seizure medication, your veterinarian may want to evaluate it earlier (7 to 10 days after prescribing the medication) to regulate the dosage accordingly.