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

Signs of Brain Cancer In Dogs

Updated: November 23rd, 2018

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?


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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.


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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.

Best,

Dr D



 

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  1. Emily on March 3, 2013 at 2:20 pm

    It’s me and Toby again. It’s been a month since my last post. Toby has been pretty good on steroids and tramadol daily but his left eye cornea is starting to cave in slightly with a large white hue covering most of his pupil. Any thoughts, anyone out there, please?

    • Dr. Demian Dressler on March 6, 2013 at 4:11 pm

      Emily, I am sorry to say there are a variety of issues that could cause this. If it is really his cornea, it could be an ulcer of his cornea, uveitis (which has different causes), or there may a problem with the orbit (where the eye sits). I am sorry but this is impossible to diagnose over the internet…sorry…you’ll have to get someone with hands on the dog to help directly…
      Best D

  2. Natalie on February 7, 2013 at 2:32 pm

    We lost our baby boy Bubba to what we were told was advanced brain cancer 🙁 there were no signs or symptoms, he had seizures back to back for days and they were getting closer and lasting longer each time, he was almost 8 years old 🙁 we were told there was nothing we could do for him so we had to make the hardest decision ever to let him cross to the rainbow bridge 3-27-12 I will never forget that date 🙁 we still miss him so much! He was a golden retriever male and we were told golden retrievers are prone to different cancers. We were told there was nothing we could do since we live in Alaska there isn’t any surgeries to treat brain cancer in dogs here, we all still miss him so much.

    • Dr. Susan Ettinger on February 9, 2013 at 10:43 am

      Natalie,
      Thinking of you. Sorry for your loss of Bubba.
      With sympathy, Dr Sue

  3. Emily on January 30, 2013 at 2:40 am

    Dear Dr. Dressler,
    My beagle, Toby, approx 12, suddenly had muscle atrophy on the left side of his head close to the top of his scull and below his eye. His bloodwork, abdominal X-ray, and abdominal ultrasound were all normal. He did have a slightly large liver. He is taking prozac( which he started about 3 months ago). He has always been schitzy dog but had an emotional breakdown when we were evacuated due to Hurricane Sandy. The vet put him on the Prozac then. Since the muscle atrophy about 3 weeks ago, he has been banging his head into everything, rubbing it everywhere he goes. He is currently taking prendisone, Prozac, and tramadol. He was very lame before the prendisone now very ravenous and aggressive. He did take a round of antibiotics too. Looks like he has a brain tumor, maybe a trigeminal nerve sheath tumor. I just want him to be comfortable. What can I do to help him?

  4. Linda on October 15, 2012 at 7:25 pm

    Heather: Your dog may indeed have insulinoma. If you haven’t already done this, you must get a paired glucose/insulin test to check what her insulin level is when her blood sugar is low. High insulin when the blood sugar is low indicates insulinoma. That would account for the seizure and the “dizzy” behavior – when a dog has a hypoglycemic episode it will act “drunk”, stagger around, have glassy eyes – that sort of thing. Insulinoma is not curable but is treatable.
    I cannot recommend this more highly. All the information and advice you need is here as well as incredible help and support from dog owners whose dogs have or have had insulinoma. My other dog has insulinoma and with surgery and now palladia she is doing well 2 years post-diagnosis. But there are several other options as well. However, you must get on it right away! Insulinoma is not common and many vets don’t know how to recognize it, never mind how to treat it properly. Read the info. on this insulinoma dog group page and get a vet/oncologist who knows what to do.
    When my dog was showing symptoms, my vet first thought it was probably a brain tumor, but she realized pretty quickly from my dog’s blood sugar (and a subsequent glucose/insulin test) that it was insulinoma. So it’s not uncommon for vets to mistake insulinoma for brain tumors.
    You posted a couple of months ago so you’ve probably figured this all out by now, but if that’s true perhaps this info will help someone else…

  5. Elle T. on October 14, 2012 at 2:24 pm

    Dear Dr. Dressler,

    My dog became aggressive towards my other pets and me about six months ago. He was always sort of curmudgeonly, and had also bitten on a couple of occasions (when he was startled – not just indiscriminately.) His new aggression also seemed to be fear-based but was more extreme. He is approx. 11 years old but could be older (when I adopted him 8 years ago they estimated his age to be 2 -3.)

    Blood tests and the like showed there was nothing wrong with him, although he has not, I feel, been thoroughly examined otherwise because of his aggression. I took him to two different vets and a neurologist. No-one checked his eyes, and I now believe he is at least partially blind, which I am wondering might not be a cause of the aggression. I think he is also partially deaf. No-one checked his hearing either. He has gotten lost in the garden and stands sometimes at the hinge side of the door, that sort of thing. But I haven’t observed any “brain tumor-y” symptoms. He has fallen off the dog stairs up to the couch because he has veered off the steps – I now believe that is because he can’t see them. One thing he does that really stresses me out is he will stand for long periods of time, almost falling asleep on his feet. Sometimes I am successful in getting him to lie down; other times he gets angry so I have to just let him stand and try again later. He can be standing around, swaying on his feet, and then when I get the leash to take him for a walk, suddenly he’s energized and perfectly co-ordinated (not that he isn’t co-ordinated otherwise, but he looks weird just standing there.) He walks fine, although he stumbles when he doesn’t see certain things, and when we get home he puts on the brakes and refuses to move. He was put on prozac a couple of months ago and that has helped with his aggression I feel, but he still has issues. When I went to the neurologist, he said the only way to tell if he had a brain tumor was an $1800 MRI, which I don’t have the money for. He said he could not, of course, make a diagnosis without that but he seemed to think it was probably a brain tumor, based mostly it seems on the “change in behaviour” – that is, the aggression. Because they couldn’t touch him, they said they couldn’t do a proper neurological exam and they really didn’t tell me anything else. He doesn’t have any unilateral issues – the word “unilateral” didn’t even come into it, so they didn’t even know that. I just feel that he has not been properly examined. I’m not convinced he has a tumor – I’m wondering if the eye issues precipitated the aggression instead of a brain tumor causing the aggression and the eye issues. Do you have any suggestion as to what I should do next? I have considered taking him to a different neurologist and getting his eyes and ears looked at. I have also considered seeing a vet. behaviourist to find out if perhaps we should try anipryl for dementia instead of prozac. Or perhaps it really is a brain tumor. I just want to make him feel as safe and comfortable and happy as possible, and I don’t feel I can do that until we get to the bottom of this. Thank you so much in advance!

  6. Susan on September 19, 2012 at 4:44 am

    Dear Dr.
    I have a 12 year old female boxer. She has a Metastasis on her side about the size of a small cantaloupe or extra large grapefruit. Last night @ 2:30 am, she had a grand Mal seizure which lasted about 10 minutes, but at least 20 more to be somewhat coherent. Once we got her up to go outside, she just wandered outside and when she came in she continued to pace, run into things, pant heavily, and would not lay down . I thought of giving her a Benedryl to maybe help her sleep and it did work after about 40 minutes. This was about 4:20am by then. Just 2 days ago, she was eating, actually running outside since it has been cooler, moving her bowels, etc. What can I expect at this point? I am so afraid of having her longer with me and that she could be in pain, etc. I had to put down my last dog of 15 years and it practically destroyed me. I just do not want to have to do that again. I always hoped she would just pass away on her own. I hope you have some words of wisdom for me. I did refuse to have the tumor removed since she is up there in years, and she seems to stress so much just going to the vet.
    Thank you,
    Sue

  7. Helen Bradbury on September 8, 2012 at 11:19 am

    I had a 9 year old white boxer called poppy who was put to sleep yesterday following a brain tumour diagnosis,I wasn’t aware of a treatment called Cyber Knife-is this treatment available in the U.K?,my vet prescribed a trial treatment of steroids but poppy’s symptoms remained the same but when she started whining + smacking her head into doors I didn’t want her to suffer any longer. I was also concerned to further problems affecting poppy from the tumour: seizures or blindness. I keep questioning my decision + hope I have done right by my. Dog?

    • Dr. Susan Ettinger on September 12, 2012 at 3:53 pm

      HI Helen,
      Sorry about Poppy. I am not aware of CyberKnife or another form of radiosurgery in the UK, but I would check with an oncologist to be sure. If not conventional radiation may still be a good option. Again, I recommend consultation with and oncologist or a neurologist.
      Good luck! All my best, Dr Sue

  8. Karen on July 29, 2012 at 11:19 am

    I just found out that my dog of 10 years probably has brain cancer and I am going to assess every week and as long as she is not in pain she will stay with me. I would never let her feel pain and at the first sign of anything I will look after her with love and let her go.

  9. Lisa on July 26, 2012 at 9:19 am

    I have a 10 y/o boxer. Within the last 3 months she has gone completely blind. The mobile vet said he thought it was nulelar schlerosis. However, she has become so anxious acting within the last two weeks that he has now put her on a depression medication. I am afraid I am prolonging the inevitable by not having her put down. She shakes and tremble including twitches of her head. The medication just makes her sleep for hours on end and when she wakes up she still so pitiful. Her appetite has dramatically decreased as well. I just have to coax her to go to the bathroom or eat anymore. What is your opinion? Should I go ahead and allow her to be at peace? Do you think she will last much longer and do you think might be cancer? I am just really upset and feel like I have no where to turn. Thank you!

  10. fiona on July 13, 2012 at 12:51 pm

    I have a 5 year old cavalier king Charles spaniel, 2 years ago he had a fit and we have not seen it happen again till last week, he has had four fits in one week, though the vet is clueless at the moment as to what it is exactly. he will lose control of his limbs, unable to stand, he sometimes can’t move one side of his body suggesting stroke..but once he comes out of the fit hes back running around like nothing has happened, he hasn’t wet himself or vomited during or after though he did have a high temp…could he have a tumor? And this be a deterioration ?

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