CONDITION
Meningioma
A meningioma is a growth that arises from the meninges, the protective membranes that surround the brain and spinal cord. These growths tend to develop slowly over months or years, and in dogs and cats they are often found in older animals. Most meningiomas grow in a way that gradually compresses nearby brain tissue rather than invading it, though the effects depend on where the growth is located and how much space it occupies. Owners often notice changes that reflect pressure on particular parts of the brain: altered behaviour, seizures that begin in middle age or later, subtle loss of coordination, changes in vision, or a head posture that seems unusual. These signs can appear gradually and may initially be attributed to normal ageing. In some cases, a meningioma is discovered during investigation of a single seizure or after imaging is performed for another reason. This page explores the patterns that can signal a meningioma, what is happening beneath those signals, how the condition is investigated, and the range of approaches that exist once a meningioma is identified. The course and options vary considerably depending on the location, size, and behaviour of the growth, as well as the individual animal.
Why this matters now
Meningiomas tend to appear in older dogs and cats, most often those beyond eight or nine years of age, though younger animals are occasionally affected. Certain breeds, including Boxers, Golden Retrievers, and domestic longhair cats, appear to develop these growths more frequently than others, though meningiomas can arise in any breed. The condition reflects a slow accumulation of changes in the meningeal cells over time rather than a sudden event.
Most meningiomas grow slowly, over months to years, and the signs an owner notices often mirror that gradual pace. Early changes may be subtle enough to blend into the background of normal ageing, becoming more apparent only as the growth occupies more space or compresses structures with less tolerance for pressure. Some meningiomas remain stable in size for extended periods, whilst others progress more steadily, and the rate of change can vary considerably between individual animals.
Signals & patterns
Early signals
Behaviour that seems altered
An owner may notice their dog or cat seems less interested in familiar activities, more withdrawn, or responds differently to household routines. These shifts can be subtle and may initially be mistaken for the effects of ageing, but they often reflect pressure on areas of the brain involved in mood and social engagement.
Seizures beginning in mid-life or later
A first seizure occurring in a dog or cat older than five or six years can signal a structural change in the brain, as seizures in older animals are less commonly due to inherited epilepsy. The pattern, frequency, and features of the seizures can vary widely depending on which part of the brain is affected.
Subtle loss of coordination
An animal may begin to misjudge jumps, drift slightly to one side when walking, or move with less precision than usual. These changes tend to develop gradually and may be more noticeable on stairs, uneven ground, or when turning.
Changes in vision or tracking
Some owners observe their pet bumping into objects on one side, hesitating before moving through doorways, or responding less reliably to visual cues such as a thrown toy. This can occur when a meningioma compresses pathways involved in processing what the eyes see.
Unusual head posture or tilt
A persistent tilt or turn of the head to one side, or a reluctance to raise or lower the head normally, may reflect pressure on structures that help the brain interpret balance and spatial orientation.
Later signals
More frequent or prolonged seizures
Seizures may increase in frequency, last longer, or become more difficult to interrupt as the growth continues to compress surrounding brain tissue. Some animals experience clusters of seizures over a short period.
Marked difficulty with movement
Coordination may deteriorate to the point where walking becomes unsteady, circling becomes pronounced, or the animal struggles to rise or navigate familiar spaces. This reflects increasing pressure on motor and balance centres within the brain.
Changes in consciousness or responsiveness
An animal may seem less aware of its surroundings, slow to respond to its name, or appear to stare vacantly. Episodes of confusion, disorientation, or altered wakefulness can occur when deeper brain structures are affected by pressure or swelling.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
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