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Brain Tumors in Dogs

Posted January 13, 2015 in Dog Diseases & Conditions A-Z

Old dog laying down

Years ago, I lost my own personal pit bull to a fast growing brain tumor. Unfortunately, in both human and veterinary medicine, brain tumors can result for no known reason. While genetics and environment may potentially have a role, the underlying cause for brain tumors is typically unknown. Breeds with “smooshed” faces such as Boxers, Boston terriers, and pit bull terriers are overrepresented with brain tumors.

While rare, the diagnosis of a brain tumor in a dog can be devastating to a pet guardian, as the onset of clinical signs is typically very rapid. Clinical signs of a brain tumor include:

  • Aggression
  • Altered behavior
  • Decreased cognitive function
  • Hearing loss
  • Blindness
  • Abnormal pupil size
  • Acute seizures
  • Constant or abnormal panting
  • Inability to walk
  • Walking drunk
  • Circling in one direction

Diagnosis of a brain tumor
The diagnosis of a brain tumor in dogs typically starts with a thorough physical examination by your veterinarian (including a careful neurologic examination to look at the pupils, the response to light, the reflexes in the limbs, etc.). Additional tests to diagnose a brain tumor include:

  • Baseline blood work to make sure the kidneys, liver, and other organs are working appropriately and to evaluate the white and red blood cells
  • Chest x-rays to make sure there is no obvious cancer spread to the lungs
  • A CT or MRI under general anesthesia to look specifically at the central nervous system

Treatment of a brain tumor
Emergency treatment for a brain tumor is often necessary – that’s because dogs often present with acute seizures secondary to a brain tumor. Unfortunately, slow growing brain tumors may encroach on the normal space of the brain. As the tumor gets bigger, it can cause pressure changes within the brain (e.g., cerebral edema), resulting in neurologic signs.

Specific treatment to stop the seizures include:

  • Placing an intravenous (IV) catheter immediately
  • Checking a blood sugar
  • Using IV diazepam (Valium™) to stop the seizures
  • Starting potent anti-seizure medications such as phenobarbital, Keppra™, or other drugs to stop the seizures
  • Using medication to decrease the swelling within the brain (e.g., mannitol)
  • Nursing care to help decrease swelling in the brain (e.g., elevating the head at a 15-30 degree angle, oxygen therapy, etc.)

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Justine has more than 18 years of experience in the veterinary industry and is a board-certified emergency critical care veterinary specialist and toxicologist as well as the CEO and founder of Vetgirl. She is also a founding member of IDEXX’s Pet Health Network team.