Signs of Brain Cancer In Dogs

Featuring Demian Dressler, DVM and Susan Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide.

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Signs of Brain Cancer In Dogs

Tumors in the brain are very tough for us in veterinary medicine today. There are two reasons for this.  One is that they are hard to diagnose without advanced imaging like CT or MRI.  These are not available to everyone, since many do not live within a reasonable distance, and they are not cheap.

The second reason is they are hard to treat.

Let’s look at both of these topics.  First, how would a vet suspect a brain tumor in a dog without the use of one of these imaging tools?

I would like to introduce some words to you.  One is “unilateral.”  When a medical problem is unilateral, it means it is occurring on only one side.  There is a phrase that you should know as well: “space occupying lesion”.  A space occupying lesion means that the problem takes up space and most commonly displaces or puts pressure on the surrounding tissue.

One of the very first things a vet will do is try to decide where in the body the problem is going on.  This is called the “anatomical diagnosis”.  We try to pinpoint the organ, tissue or system that we believe is the location of the issue in the body.

Next,  vets will usually come up with a list of possible disorders that could affect that area.  These are the “differential diagnoses,” which means a list of different possibilities that are ranked in order of what is most likely to what is least likely.

When we create these possibility lists, we will use information about the dog to help narrow them down and rank them.  Age is a big one.  Certain diseases are more common in young dogs and certain are more common in older dogs.  Breed is another since certain breeds are more prone to certain problems.

Sex is another, and whether a dog has been spayed or neutered.  All of these things impact probabilities.

The history you give a vet will also help. Did the problem start suddenly or slowly?  What about appetite, thirst, and other signs of illness? Is it worsening?

Is there weight loss?

The physical exam helps a lot.  Here is where the rubber meets the road with brain cancer, and the words you learned above come into play.

When we think about brain cancer, most of the time the dogs will have some sort of brain sign.  These include seizures, blindness, and other obvious signs like that.  (Note that other body parts can be diseased and produce these signs.)

Now, one key point your vet may pick up is that the brain signs in a dog are unilateral- they issue seems to be affecting one side more than the other.  When this occurs, there is some assymetry going on.  One side is different from the other.

Perhaps we have a loss of coordination, but it affects the left side more than the right side.  Or maybe a pupil is dilated or constricted in the right eye but not the left.  Possibly the retina (seen by looking in the eyeball) looks different on one side.  Could be there is a droop or weakness in the muscles of the face.

These all point to things that are assymetrical.

If it looks like the problem is in the brain (which is concluded after laboratory testing), there are not many common brain problems in dogs that affect one area of the brain but not other areas.  One of the most common is a space occupying lesion, or a tumor.

But wait!  Other things can do it too.  For example, a stroke (vascular accident) can sometimes happen in dogs.  A common one is a problem with the vestibular system, which is responsible for keeping balance. This is called geriatric vestibular syndrome. Rarely, inflammation or infections can do it.  These all can have signs that affect either the left or right side of the body.

Now, more information can be gathered to help sort these things out.  A critical piece of information for us is what is happening with the problem over time.  Strokes most commonly stay the same severity or get better.  Geriatric vestibular syndrome almost always gets better.

Tumors however do not.  They progress.  Inflammation and infections in the brain get worse too.

Most of the time one can rule out the majority of the brain inflammation and infections with blood work and a spinal tap.

So if the problem is pointing to brain (the organ), in an older dog, and it seems like it looks assymetrical (affecting a single area but not the adjacent area), it is progressing over time, and lab testing rules out the other things that can look like it, we are left with brain tumor as number one.

This is how vets will sometimes talk about brain tumors without the benefit of a CT or MRI. They are talking about the highest probability.

As far as treatment is concerned, doing brain surgery on dogs is not routinely done simply because most of the time the technique has not been well worked out.  There are some rare neurosurgeons out there that have done it successfully but they are few and far between.

However, there is a new technology out there in New York that can help.  Dr. Sue Ettinger, an oncologist who is working with me on the second edition of The Dog Cancer Survival Guide, works at The Animal Specialty Center. The facility houses the most sophisticated tool for treating brain tumors in dogs in the country.

It is called the Cyberknife.  The apparatus is capable of directing many small doses of radiation at brain tumors in dogs from multiple directions during the treatment, in an effort to destroy the tumor without harming the patient.

Other approaches I discuss with my clients in the Guide include diet, supplements like Apocaps, life quality enhancement, touch therapies, and considering homeopathy.  A closer look at homeopathy in brain tumors, in particular gliomas, can be found here.

Please keep your vet involved in all steps in your dog’s treatment plan.


Dr D

About the Author: Demian Dressler, DVM

Dr. Demian Dressler, DVM is known as the "dog cancer vet" and is author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog's Life Quality and Longevity.

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