Glioma in Dogs

A glioma is a tumour that arises from the supporting cells inside the brain itself — the glial cells that surround and insulate nerve tissue. These tumours grow within the substance of the brain, rather than on its surface or in surrounding structures, and their behaviour varies: some are low-grade and slow-growing, but the most common form in dogs is high-grade and progresses more rapidly. Owners often arrive on this page because their dog has developed changes in behaviour, coordination, or awareness that have persisted or worsened — perhaps seizures that have begun in an older dog, a head tilt or circling that does not resolve, or subtle shifts in personality or responsiveness. These signs reflect disruption to specific regions of the brain, and the pattern depends on where the tumour is located and how quickly it is expanding. This page explores what those early signals can look like, what is happening beneath them, how gliomas are investigated using imaging and sometimes biopsy, and what approaches exist — from monitoring and supportive care to surgery, radiation, and chemotherapy. The aim is to help you understand the landscape, not to prescribe a path.