Brain Tumors in Dogs
Key takeaways
Brain tumors in dogs are abnormal growths of cells within the brain.
- Either primary (originate directly from the brain cells) or secondary (originated somewhere else in the body)
- There are a lot of different types of tumors that can affect the brain, the most common ones are meningiomas and gliomas
- The cause of brain tumors is mostly unknown
- Likely due to a combination of risk factors including breed, age, and environmental factors
- Clinical signs vary depending on the size, stage, and type of tumor
- Symptoms include seizures, circling, ataxia, lethargy, behavioral changes, nystagmus, paresis, and head tilting
- Diagnosis includes bloodwork, urinalysis, cerebrospinal fluid analysis, and diagnostic imaging
- Treatment varies depending on the type of tumor
- The ideal option is surgical removal
- Chemotherapy, radiations, and palliative therapies are also valid options
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A closer look: Brain Tumors in Dogs
Brain tumors can be extremely dangerous and life-threatening if they damage the surrounding brain tissue. Due to the location of the growth, treatment is not always available or possible. Brain tissues do not regenerate, so surgical removal is often impossible due to the grave repercussions it can have on the quality of life.
The most common type of brain tumor to occur in dogs are meningiomas, which are slow growing tumors that develop from the tissue lining the brain. These tumors are typically found on the brain surface, compressing the brain tissue underneath. Meningiomas are more common in dolichocephalic breeds (e.g. Collies), and commonly develop in dogs older than 9 years of age.
Other possible brain tumors that can occur in dogs are astrocytomas, choroid plexus tumors, oligodendrocytomas, and gliomas. These tumors tend to develop within the brain itself.
The prognosis depends on the type of tumor and other factors such as its size, its behavior, and its location. Overall, dogs that are diagnosed with brain tumors have a life expectancy of only a few months.
Risk factors
Brain tumors are uncommon in dogs. They can affect dogs of all ages, but are mostly seen in older dogs. Some breeds, such as Golden Retrievers and Boxers, seem to be particularly predisposed to developing brain tumors.
Some breeds are particularly predisposed to certain types of brain tumors. For example, dolichocephalic (long-nosed) breeds are more predisposed to meningiomas, while brachycephalic (short-nosed) breeds are more predisposed to glial cell tumors and pituitary tumors.
Depending on the location, stage, and size of the tumor, clinical signs might appear more severe.
In some cases, brain tumors can lead to blindness, sleep disorders such as narcolepsy and cataplexy, tremors, paralysis, and locomotor disturbances.
Possible causes
As for many tumors, the cause is mostly unknown.
The development of brain tumors is likely due to a mix of risk factors such as genetic predisposition and age.
Main symptoms
Symptoms may vary depending on factors such as the size and the type of tumor.
Testing and diagnosis
The diagnostic process consists of:
- Physical examination
- Bloodwork
- Urinalysis
- Cerebrospinal fluid samplesDiagnostic imaging of the brain such as MRI, CT scanning, and X-rays to identify the type of tumor, its location, and its size
A biopsy of the brain tumor is usually not recommended because of the risks and cost it entails.
Steps to Recovery
The main goal of treatment is to reduce pressure within the brain and reduce the size of the tumor.
Treatment possibilities include:
- Surgery, if full removal of the tumor is possible
- Chemotherapy or radiation therapy to try and reduce the size of the tumor
- Palliative care including steroids and anti-seizure medications
Prognosis is generally poor with brain tumors. The life expectancy with treatment varies depending on the type, size, and stage of the tumor. Many dogs survive less than a year after diagnosis of a brain tumor.
Similar to other tumors, the earlier they are discovered and treated, the better the chances of successful treatment.
Prevention
There are no proven preventatives for brain tumors.
Brain tumors are not contagious.
Is Brain Tumors in Dogs common?
Brain tumors are uncommon in dogs, but are more commonly seen in older dogs.
Typical Treatment
- Surgical removal
- Radiotherapy
- Chemotherapy
- Palliative therapies
