Brain Tumor in Dogs - Types, Treatment & Prognosis

Brain Tumor in Dogs - Types, Treatment & Prognosis

Author Dr. Iva Pejnovic, DVM


Your dog was diagnosed with a brain tumor. After this shocking news, you would probably Google it. And find this article. So we will try to give you some information about this disease and how to improve the quality of life of your dog. Take a minute and read the rest.

What is a brain tumor in dogs?

Tumor medically means abnormal and uncontrolled growth of tissue cells. The brain tumor in dogs is neoplasia, a mass of neurogenic cells which can be benign or malign. It can also be:

  • primary - which means that it's the main tumor location, or
  • secondary -  metastasis of a tumor located on the other organ.

Primary brain tumor

Primary brain tumors include tumors arising from cells forming the surface of the brain (meningioma), the lining of the ventricle (ependymoma), and the choroid plexus (secretory tissue from the brain ventricle) or the brain parenchyma itself (glioma). Clinical signs depend on tissue origin and its location. Most common signs are seizures, ataxia, behavioral changes, and head tilt, but tumors can also result in nose bleeding, closing one eye, losing coordination, etc.

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Age, gender, risk factors

Primary brain tumors in dogs typically affect older dogs, 4-13 years old, with a median age of 9. Gliomas can be seen in younger dogs. There is no sex predilection. Some studies have shown that dogs over 33 lbs (15 kgs) have increased risks of meningioma. Metastases often affect the cerebrum.

Dog breeds

  • primary intracranial neoplasia: Boxer, Boston Terrier, Rat Terrier, Golden Retriever, French Bulldog
  • meningiomas: dolichocephalic breeds such as Setters, Collies, Greyhounds, Dachshunds, and Great Dane
  • gliomas: brachychepalich breeds such as Pekingese, Lhasa Apso, Brussels Griffon, Cane Corso, Bullmastif, Boxer and Bulldog
  • paranasal meningiomas: mesocephalic breeds such as Pomeranians, Beagles, Golden Retrievers, Labrador Retrievers, German Shepherds

dog looking

Doberman Pinschers and Cocker Spaniels were found to have a significantly decreased risk of primary intracranial neoplasms.

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Clinical signs

Clinical signs vary with tumor location. Usually, brain tumors in dogs cause signs by compressing or invading the brain, so clinical signs relate directly to the area of the brain affected and are not specific to a tumor. Symptoms can be acute if vascular invasion results in focal ischemia or if edema develops rapidly. Neurologic signs predominate.

First is abnormal behavior and mentation, coordination, and proprioceptive deficits. Seizures can present symptoms without evidence of neurologic examination deficit. Ataxia and motor dysfunction vary with the location of the tumor. Also, neck and back pain can occur. Cats can develop anisocoria and stupor.

1. The forebrain

The forebrain is responsible for sensory information. If the forebrain is affected by a tumor, we can expect seizures. If the new onset of seizures affects older animals, they should be taken for a complete checkup. Other signs of the forebrain tumor can be a loss of learned behavior, depression, circling, decreased awareness of body posture causing misjudgment of the body's position in the room and increased or decreased appetite or thirst.

2. The brainstem

The brainstem is responsible for vital functions such as the ability to walk or respiratory and cardiovascular systems. Suppose the brainstem is affected by a tumor. In that case, it can lead to various clinical signs, including weakness of one side of the body, change of voice, swallowing, the inability to move eyes, or paralysis. Typically first signs of the brainstem disease can include vestibular symptoms like head tilt, strabismus, nystagmus, etc. Tumors of the brainstem can be fatal if they affect the respiratory center.

sad dog

3. The cerebellum

The cerebellum closely interacts with the vestibular system and controls posture and coordination of movements. If the tumor affects the cerebellum, clinical signs can include wide-based stance, head tilt, head tremors, uncoordinated gait, or swaying of the trunk.

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Secondary brain tumor in dogs

Secondary brain tumors represent the metastasis of another tumor located anywhere in the organism. The prognosis is very poor because they have already spread through the body.

The goal is to improve the quality of life with no pain by providing palliative treatment.

How can my vet diagnose a brain tumor?

Considering the signs you've described, your vet can suspect a brain tumor and take some medical tests. The basis of all is neurologic examination. The second one is imaging. Because the brain cannot be seen on the x-rays, diagnosing can be based on imaging with a CT or MRI scan. These tests are perfect for detecting a presence of a mass, but they are not good at detecting the nature of the mass.

To confirm the exact cause of mass, an example of mass or cerebral fluid must be collected at the time of surgery. Aggressive malignant tumors can spread in the body, and usually, metastasis affects the lungs, prostate, liver, or mammary gland. X-rays and ultrasound can confirm or deny the existence of metastasis.

Can tumors be treated?

Unfortunately, there are only a few tumors that can be cured. But the rest can be treated with good life quality. The treatment and prognosis vary by the type and location of the tumor. The most appropriate treatment depends on individual factors.

1. Medication

Most medications cannot penetrate the brain, but there are a few chemotherapeutics that can be used. Combining corticosteroids to reduce swelling and pressure with anti-seizure medication can reduce the frequency and severity of seizures. However, this combination can make a pet more thirsty (more urinating) and also more sleepy.

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2. Medication and radiation therapy

The advantage of using radiation treatment and medication is that it can provide a longer period of quality of life than with medication alone. Unfortunately, radiation cannot completely destroy the tumor, and it can affect other healthy organs, but side effects can be under control by symptomatic therapy.

black dog

3. Medication, radiation therapy, and surgery

Combining all three potentially offers the longest period and quality of life. The goal of surgery is to eliminate the tumor mass from the brain. Still, unfortunately, it is rarely possible to eliminate the whole mass, and there are almost always some tumor cells left behind, which makes the tumor regrowing. Not all brain tumors can be removed surgically.


The aim of treatment is to provide the best life quality without suffering and pain and to prolong the pet's life as much as possible. Predicting how long a pet can live is practically impossible. Prognosis varies, but average remission time ranges from 1 to 12, maximum of 20 months, depending on all the factors above: location, progression, clinical signs, age, and type of treatment. Many pets can live months after diagnosing a brain tumor. As with any cancer, the earlier it is diagnosed and treated, the better the chances that treatment will be successful. Dogs with brain tumors must have regular checkups for any signs of regrowth.

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Euthanasia-yes or no?

A brain tumor diagnosis can bring that conversation around much earlier than expected. It is not a sad and cruel act; it is an act of relieving your pet of pain and discomfort. Some signs that show you that it is time to discuss this option with your vet include a complete loss of appetite, inability to move, inability to control bladder and bowel, behavioral changes including aggression, and extreme pain when medications cannot help. If you think your pet's quality of life is decreasing rapidly, you should consult your vet about euthanasia options.

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A brain tumor is a mass of uncontrolled and abnormal brain cells. It can be primary in the brain or secondary metastasized from another place in the body. Usually affect older dogs and cats. To confirm this horrible disease, your pet should be taken on a CT scan or/and MRI scan. Depending on mass location and type, clinical signs can vary from mild neurologic to paralysis and frequent seizures. They can be treated medically, by radiotherapy, or by surgery, including a combination of all three. Most of the time, therapy is based on improving the best life quality. Most of the tumors cannot be cured, even fully surgically removed, so in most cases, they regrow, and the prognosis is not very well. If you think your pet's life quality is decreasing or your pet is in pain, you should consider euthanasia.

World Dog Finder team

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