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Brain Tumors in Dogs

By the Dog Health Handbook team · Updated · Fact-checked against current veterinary references (see sources)

Key takeaways

  • A first seizure in a dog over about 5 or 6 should be checked for a brain cause.
  • Meningiomas are the most common primary brain tumor, followed by gliomas.
  • MRI is the best test, but it can't always tell a tumor from inflammation.
  • With comfort care alone, dogs live a median of about 2 months.
  • Radiation often gives 1 to 2 years for meningiomas.

Table of Contents

Research Types Signs Lookalikes Diagnosis Treatment Comfort care Final stages FAQ Sources

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Brain tumors in dogs are found in about 2% to 5% of dogs examined after death, and most affected dogs are older than 5, with an average age at diagnosis of about 9.1,2,3 The most common sign is a seizure, especially a first seizure in a dog older than about 5 or 6. Behavior change, circling, wobbliness, a head tilt or vision loss are other signs.4,5,6 Meningiomas, which grow from the brain's covering, are the most common primary brain tumor, followed by gliomas.5,1 MRI is the best test.1 Treatment ranges from comfort care with steroids and anti-seizure medicines, with a median survival of about 2 months, to radiation, alone or after surgery, which often gives a year or more for meningiomas.7,8,5

Go to an emergency vet if your dog:

  • Has a seizure lasting more than 5 minutes, or several seizures close together9
  • Suddenly goes blind1

Book a prompt vet visit for a first seizure in an adult dog, ongoing behavior change, circling or pressing its head against walls.5,10 See seizures in dogs for first aid.

What the Research Says

  • Radiation outperformed surgery for meningioma. In a 2025 study of 285 dogs at 11 specialty clinics in the US, UK and Japan, median survival was 696 days after radiation and 297 days after surgery.8
  • Tumor location matters for comfort care. Dogs treated only with steroids or anti-seizure medicines lived a median of 178 days with forebrain tumors but 28 days with tumors at the back of the brain.7
  • Age changes the odds. In an MRI study of 312 dogs with seizures, each extra year of age raised the odds of a brain mass, and more than half of dogs over 7 had one.11
  • Fewer radiation sessions can work. In 59 dogs given three-session stereotactic radiation, median survival was 738 days.12

Types of Brain Tumors in Dogs

TypeWho gets itTypical outlook with treatment
Meningioma (from the brain's covering)About half of primary tumors; older dogs (median about 10.5), larger and long-nosed breeds such as Golden Retrievers5,1,2Radiation: often 1 to 2 years. Surgery alone: about 7 to 10 months8,5,13
Glioma (from brain support cells)About a third of primary tumors; median age about 8; Boxers, Boston Terriers and bulldogs5,1Usually weeks to months; some dogs about a year with radiation14,5
Pituitary tumor (at the base of the brain)Common; more often in short-nosed breeds; can cause sudden blindness1Can be long with radiation1
Choroid plexus tumorAbout 7% of primary tumors; younger dogs (median about 5.5)5Limited data5
Secondary tumor (spread from or growing in from elsewhere)About as common as primary tumors; hemangiosarcoma and nasal tumors are common sources5,1,2Usually comfort care1

Meningiomas are often described as benign because their cells look less aggressive, but in dogs they tend to grow into the brain, so they can still be serious because of where they grow.3,4

Signs of a Brain Tumor

Early signs can be subtle, such as a single seizure or a small change in behavior, so they are easy to miss at home.5,3 Signs depend on where the tumor is:7,5

Tumor locationCommon signs
Forebrain (front and top of the brain)Seizures, behavior change, confusion, pacing or circling, vision loss, head pressing5,4,10
Back of the brain (cerebellum and brainstem)Head tilt, wobbly walking, flicking eyes, trouble swallowing7,5,4
Pituitary areaSudden blindness, neck pain, hormone problems1,3

Seizures occur in about half of dogs with forebrain tumors and may be the only sign.5,3 A first seizure in a dog older than about 5 or 6 should be checked for a brain cause. Dogs whose seizures start before 6 are much more likely to have epilepsy than a tumor.6,4,5 Signs usually worsen gradually over weeks to months.5,7

What Else Could It Be?

ConditionHow it differs
Idiopathic epilepsySeizures usually start between 6 months and 6 years, with a normal exam between seizures6
Old dog vestibular diseaseSudden head tilt and imbalance that improve within days; most dogs recover in 2 to 3 weeks15
StrokeSudden onset, often stable after the first 24 hours3
Inflammatory brain disease (MUO)Often younger small breeds; can look like a mass on MRI16
Cognitive dysfunction (dementia)Slow changes in sleep, house training and recognition; diagnosed after other causes are ruled out3
Liver disease, low blood sugar, toxinsBlood and urine tests find these13,10

See neurological problems in dogs for other causes.

Diagnosis: MRI and CT

Your vet will start with a neurological exam and blood and urine tests to rule out other causes, and chest and abdominal imaging to look for cancer elsewhere.13 MRI is the best test for a brain tumor. CT is less detailed but useful for bone. Both need a general anesthetic.1,13 A spinal fluid sample may also be taken.1

MRI usually shows whether there is a mass, but it can't always tell a tumor from inflammation, or which type of tumor it is. Imaging-based diagnoses were wrong in about 30% of cases, and a biopsy, the only sure test, isn't always possible.1,17,16

Treatment Options

TreatmentWhat it involvesTypical median survival
Comfort careSteroids to reduce brain swelling and anti-seizure medicines at home7,13About 2 months: weeks for tumors at the back of the brain, several months for forebrain tumors7,5
Radiation (conventional)Daily treatments over about 3 to 4 weeks, each under anesthesia1About 1 to 2 years for meningioma; shorter for glioma8,5
Stereotactic radiationHighly focused radiation in about 1 to 4 sessions1,12Similar to conventional radiation in studies so far8,18
SurgeryRemoval of tumors near the brain surface, mainly meningiomas1,13About 7 to 10 months alone; longer with radiation afterward13,5
ChemotherapyDrugs that reach the brain, sometimes after surgery or radiation1,19Evidence that it lengthens life is limited5

For meningiomas, radiation alone or surgery followed by radiation usually gives the longest survival.8,5 Stereotactic radiation needs much less anesthesia and has given similar results, but it may carry a somewhat higher risk of serious side effects. Ask a radiation oncologist whether it suits your dog.18,8 Surgery and radiation each carry risks: in reviewed studies, about 1 in 10 dogs died after surgery, and about 1 in 10 had side effects or died after radiation.5 See dog cancer treatment for approximate radiation costs.

Comfort Care at Home

  • Steroids can reduce swelling around the tumor within 24 hours. Some dogs improve dramatically for weeks or months. Expect more thirst, urination and hunger.3,4,19
  • Anti-seizure medicines are given as your vet directs. Keep a diary of any seizures.13,9
  • Safety: during a seizure, keep your dog away from stairs and furniture and keep your hands away from its mouth.9
  • Pain: some dogs have neck pain, especially with pituitary tumors, and pain control is part of palliative care. Tell your vet if your dog cries out, avoids having its head touched or seems restless.1,4,20

Final Stages of a Brain Tumor

As the tumor grows, seizures often become more frequent, and dogs may become disoriented, vocalize more, have flicking eye movements, stop eating and lose weight.21 Trouble swallowing raises the risk of pneumonia.4 When seizures can't be controlled or your dog no longer enjoys daily life, talk to your vet about quality of life and when to say goodbye.21,7

Frequently Asked Questions

What are the first signs of a brain tumor in a dog?

A first seizure in a dog over about 5 or 6, a change in behavior, circling, a head tilt or wobbly walking.

How long can a dog live with a brain tumor?

With comfort care only, about 2 months on average. With radiation, often 1 to 2 years for meningiomas, but less for gliomas.

Is a dog with a brain tumor in pain?

Some dogs have neck pain or seem uncomfortable, and steroids often make them feel better. Your vet can add pain relief if needed.

Can a brain tumor in a dog be cured?

Rarely. Surgery can sometimes cure a meningioma, and radiation can control some tumors for a year or more, but most brain tumors eventually progress.

Should I treat my dog's brain tumor?

It depends on the tumor type and location, your dog's health, your goals and costs. Ask a neurologist or oncologist about the likely benefit of each option, including comfort care.

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Sources and further reading

This article was rewritten and fact-checked on October 29, 2026 against current veterinary references and specialist guidelines:

  1. Williamson B (reviewed by Carnevale J). Neoplasia of the nervous system in small animals. Merck Veterinary Manual (professional version), full review October 2025, updated March 2026.
  2. (Authors not shown on fetched page.) Postmortem evaluation of 435 cases of intracranial neoplasia in dogs and relationship of neoplasm with breed, age, and body weight. Journal of Veterinary Internal Medicine 2013.
  3. Platt SR. Brain diseases of geriatric dogs and cats. EVC Voorjaarsdagen, The Hague, 2016 (hosted by IVIS).
  4. Weir M, Barnette C, Downing R. Brain tumors in dogs. VCA Animal Hospitals, updated June 20, 2025.
  5. Miller AD, Miller CR, Rossmeisl JH. Canine primary intracranial cancer: a clinicopathologic and comparative review of glioma, meningioma, and choroid plexus tumors. Frontiers in Oncology 2019;9:1151.
  6. De Risio L, et al. International Veterinary Epilepsy Task Force consensus proposal: diagnostic approach to epilepsy in dogs. BMC Veterinary Research, 2015.
  7. (Authors not shown on fetched page.) Survival time following hospital discharge in dogs with palliatively treated primary brain tumors. Journal of the American Veterinary Medical Association 2013;242(2):193-198.
  8. Geiger R, Mankin J, Volk HA, de Decker S, van Asselt N, Randhawa K, et al. Comparison of survival after treatment of presumed intracranial meningioma by radiotherapy or surgery in 285 dogs. Journal of Veterinary Internal Medicine 2025;39:e70011.
  9. Barnes C, Weir M, Ward E, Gollakner R. Seizures in dogs. VCA Animal Hospitals, January 2026.
  10. Koehler R. Head pressing in dogs: causes, diagnosis, and treatment. PetMD, April 23, 2024.
  11. Walsh N, Carney PC, Streu S, Thompson M, Johnson PJ. Prevalence of brain magnetic resonance imaging diagnoses and correlation with signalment and presenting complaint in dogs. Frontiers in Veterinary Science 2021;8:768709.
  12. Carter GL, Ogilvie GK, Mohammadian LA, Bergman PJ, Lee RP, Proulx DR. [A robotic stereotactic radiotherapy system] stereotactic radiotherapy for treatment of primary intracranial tumors in dogs. Journal of Veterinary Internal Medicine 2021;35:1480-1486.
  13. University of Missouri Veterinary Health Center. Brain tumors. Published July 8, 2016, modified July 12, 2016.
  14. Jose-Lopez R, Gutierrez-Quintana R, de la Fuente C, Manzanilla EG, Suñol A, Pi Castro D, Añor S, Sánchez-Masian D, Fernández-Flores F, Ricci E, Marioni-Henry K, Mascort J, Matiasek LA, Matiasek K, Brennan PM, Pumarola M. Clinical features, diagnosis, and survival analysis of dogs with glioma. Journal of Veterinary Internal Medicine 2021;35(4):1902-1917.
  15. Hyland K, Barnes C, Weir M, Ward E. Vestibular Disease in Dogs. VCA Animal Hospitals, updated September 2026.
  16. Patterson A. Meningoencephalomyelitis of unknown origin in dogs. Veterinary Ireland Journal, November 2023.
  17. Wouters E. MR images for characterizing canine primary brain tumors: a comparison with histopathology. EVC Voorjaarsdagen, Amsterdam, 2013 (hosted by IVIS).
  18. Bartel J. A promising approach to treating canine brain tumors. NC State College of Veterinary Medicine news, undated (accessed October 2026).
  19. American Animal Hospital Association. Table 5.1: Overview of antineoplastic chemotherapy and immunotherapy agents commonly used in veterinary medicine. 2026 AAHA Oncology Guidelines for Dogs and Cats, 2026.
  20. Gruen ME, Lascelles BDX, Colleran E, et al. 2022 AAHA pain management guidelines for dogs and cats. Journal of the American Animal Hospital Association, 2022.
  21. Lap of Love Veterinary Hospice. What to expect if your dog has been diagnosed with a brain tumor. Lap of Love blog, undated (accessed October 2026).

About this article

Last updated : new page written using the Merck Veterinary Manual, the University of Missouri, NC State University, the International Veterinary Epilepsy Task Force, studies published 2013 to 2025 and IVIS-hosted proceedings; includes the research summary, types table, signs by location, lookalikes, diagnosis, treatment table, comfort care, key takeaways and FAQ.

This page is for general information and is not a substitute for an exam by your veterinarian.