Glioma is the name for one of the various different types of brain tumours that dogs can develop during their lifetimes, and this is actually the second most common type of malignant brain tumours that can be found in dogs overall. Gliomas are more common within brachycephalic dog populations than in dog breeds with longer muzzles and a more natural conformation – such as the Boston terrier, as well as other popular flat-faced breeds like the Boxer and the French bulldog. In fact, around 50% of all confirmed cases of glioma in dogs occur in brachycephalic breeds.

If you own a Boston terrier or another brachycephalic dog breed, it is wise to learn a little bit about canine glioma, its symptoms, and how to tell if your dog is at risk of developing a cancer of this type.

In this article we will look at canine glioma in more detail, covering the risk factors, symptoms, and treatment options for dogs with the condition. Read on to learn more.

What is a glioma?

A glioma is a type of brain tumour; a mass or growth that forms on the brain itself. Gliomas form within brain tissue, and can be hugely variable in terms of their severity and rate of growth, ranging from slow and low-grade through to highly aggressive and malignant.

Exactly where within the brain a glioma grows can be variable too, with the temporal lobe or frontal lobes being the most common places for gliomas to develop.

Gliomas are the second most common form of brain tumours that dogs can develop, and they’re not restricted to canines either; glioma formation can also occur in people, and follow a very similar progression to that in dogs.

What sort of dogs are at risk of glioma?

Glioma is one of the most common forms of brain tumour, and one that is the subject of a lot of research due to its prevalence, and the fact that it is not exclusive to dogs. Any dog can potentially develop a glioma, but brachycephalic dog breeds have the highest risk factors for the condition.

We don’t know for sure why this is, and the answer to this question is the subject of a lot of research and study; but the conformation of a brachycephalic dog’s head and muzzle, which in turn can alter the normal shape and structure of the skull and potentially, brain too, is likely to be the reason for the elevated risk.

What sort of age of dog might be affected by glioma?

Theoretically gliomas can develop in dogs at any time, and because symptoms can take a long time to become apparent, you may never know for sure when the tumour itself began to form. Whilst there are always the odd exceptions, gliomas tend to develop in dogs that are mature or entering old age; dogs over the age of seven are those most likely to be diagnosed, and gliomas in dogs under the age of around five or six are very rare.

The risk factors for developing glioma increase exponentially for every year that your dog ages, and so if you own an older brachycephalic dog like a Boston terrier, it is important to learn a little bit about this type of cancer and know what warning signs to look out for.

The symptoms of glioma in dogs

The symptoms of glioma in dogs can be variable, subtle and hard to pinpoint, as well as being common to a number of other conditions too, which can make diagnosis harder. The symptoms and the impact that they have upon the dog in question can also vary a lot depending on what area of the brain the tumour has grown on and so, affected, which makes identifying the early symptoms of the condition harder again.

Additionally, glioma symptoms in dogs won’t necessarily relate to the head, nor cause signs of pain; it is more likely that you will notice changes and anomalies in your dog’s temperament, behaviour and balance.

Look for signs such as an unsteady walking gait, erratic or repetitive behaviour like pacing or circling, head tilting or holding the head offset, head pressing, and potentially the onset of seizures.

Affected dogs may also suffer changes to their appetite and willingness to eat, either having a voracious thirst and appetite, or going off their food entirely.

Can glioma be treated or cured?

Your vet will need to run a range of diagnostic tests to reach a firm decision on the cause of your dog’s symptoms, which may well include an MRI or CT scan, as well as blood tests, a physical examination, and talking to you in depth about your dog’s health history and symptoms.

Whilst not all gliomas can be treated or cured, many can – and the earlier your dog is diagnosed and begins treatment, the higher their chances of making a recovery.

If your vet decides that they can operate on the tumour successfully, this is often the most viable option, but if this is not possible then you may need to consider chemotherapy. This may put the tumour into remission and greatly reduce the chances of it affecting your dog’s quality of life, or may mean that the tumour can be shrunk sufficiently to make surgery a viable option.

For dogs for which recovery and treatment is deemed unviable, your vet will be able to support you with your dog’s palliative care to keep them comfortable and free to enjoy a good quality of life during their remaining time with you.