Brain
tumors- are they hereditary
Question: Dr.Mike, I am a subscriber. This past summer
my 11 yr. old standard poodle was euthanized because
he started having seizures and other symptoms that are consistent
with a brain tumor. Is there any
information on weather this condition is thought to be hereditary.
I had 1 small litter of 3 pups from him
one of which I kept. At this time I'm not considering standing
the dog at stud. He is 2 yrs. old but at
some point in the future it may be a possibility. I sure don't
want to produce puppies if this is thought
to be hereditary. I can't seem to locate any information on
it on the internet. The dog I euthanized was
very special to me and so is his son. I would like to continue
on with his bloodline but don't want to go
through the heartbreak again much less put someone else through
it by selling them a puppy that
might have this problem. Thanks, Kathy
Answer: Kathy-
At the present time, to the best of my ability to research this, there
simply isn't very much information
about heredity and brain tumors. The most common forms of brain tumor
in dogs are gliomas and
meningiomas, although other types of brain tumors occur. There seems
to be an increased incidence
of gliomas in short-nosed (bradycephalic) dog breeds, like pugs and
Boston terriers. Meningiomas
occur more frequently in male cats than in female cats (Deweby, et
al, Compendium on Continuing
Education, August 2000) but these are the only links to heredity or
genetics that I can find for brain
tumors. This information may change as time goes on, so it would be
good to check again right
before making the decision to breed your dog but at the present time
there is no strong evidence that
brain tumors are hereditary, that I can find.
Mike Richards, DVM
12/16/2000
Brain Tumor
Brain tumors often have some identifiable clinical symptoms since they
often damage nerves exiting the brain or the centers that control these
nerves. Gait abnormalities, facial paralysis, vestibular disorders, blindness,
or other signs of nervous system damage may occur with a brain tumor, helping
to identify it.
Mike Richards, DVM
Seizures
-possible brain tumor - Poodle
Q: I have a nine year old poodle who started having
seizures for the first time in her life on May 12. After two weeks of having
one, or sometimes two seizures a night, the seizures suddenly stopped.
I was ready to go get an mri last week, but the machine was broken. Then
the seizures stopped. My question is this: if it were a brain tumor, would
the seizures have stopped for ten days. If she continues to be free of
seizures, can I go ahead and assume it is not a brain tumor because if
it were, the seizures would have continued? Her bloodwork was normal, which
is my vet and I were thinking tumor. But now I think, and my vet cautiously
agrees, that it is probably not a tumor. What are your thoughts?
A: While I agree that I probably would put off
doing the MRI until the recurrence of symptoms, I am not sure that I consider
the stop in seizure activity as a definite sign that a brain tumor is not
present. There can be a lot of variance in the clinical signs associated
with any cancer and it would not necessarily surprise me that the seizuring
started and then stopped if a tumor is present. If you would consider chemotherapy,
radiation or surgery as acceptable alternatives in the case of a brain
tumor, it would probably be best to do the MRI and catch the problem early.
If you are seeking prognostic information in order to make decisions about
euthanasia or palliative therapy it may not be nearly as important to know
what is going on right at this stage. I hope all is still well and I am
just being pessimistic.
Mike Richards, DVM
Part 2 - continued - getting the facts
Q: Thank you for your response. Chemotherapy, radiation,
and brain surgery scare me, but I would like to do more reading on the
subject, in order to make an informed decision. Do you know how I can better
educate myself about the effectiveness of chemotherapy, radiation, and
brain surgery as treatment for brain tumors in dogs? I would like to know
survival rates, side effects, dangers, etc. I have been trying to search
for literature on these topics, but I have not been successful in finding
the specific information I am looking for. It has all been very general.
I feel I need to do what is best for my dog, and in order to decide that,
I need as much objective information as possible. Thanks again. Pat
A: Pat- There was a Clinics of North America on
intra-cranial disease that was published within the last few years. I am
on the road and not able to give a specific reference as to the month or
year but remember that it was published. Your vet may subscribe to this
journal and be willing to let you read his or her copy. If not, your librarian
may be able to help you locate the information. I find that librarians
really like to help with serious research and are very helpful and sometimes
very resourceful at locating references.
Calling a veterinary school and asking to talk to their neurologist
can be helpful, too. Once in a while you have to get your vet to call but
if you write a list of the questions you need answers to your vet should
be able to get them for you. If your vet is a member of the Veterinary
Information Network (tm) or NOAH (the online program of the American Veterinary
Medical Association), he or she may be able to locate literature sources
for you through their databases. If you live near a veterinary college
you can probably use their library if you drive there.
Finding information can be difficult but if you get one good source,
check the references it lists and then look at those and repeat the process
you can usually find what you need.
Mike Richards, DVM
Cerebrovascular
accident or brain tumor - American Eskimo
Q: Our vet said our 12 year old American Eskimo
could possibly have had a stroke or a brain tumor. The problem seemed to
start when he got excited about going for his walk and slipped and fell.
He cried and had difficulty getting up. The vet folded his left front leg
back and he would not straighten it. It's been down hill since then. He
still gets excited about going for his walks, but he frequently stumbles
and falls down. Also he drags his left legs so that the fur has worn off
the top of his feet. He has always been a picky eater, but this past week
he refuses to eat at all. I have been able to hand feed him a little ham
or turkey or a cracker, but not enough to keep him alive very long. Any
help would be appreciated.
A: n- While the symptoms you are seeing are very
likely to be from a brain tumor or from a cerebrovascular accident it may
be a good idea to ask about referral to a veterinary neurologist. Your
vet can arrange this. In the meantime, nursing care does sometimes make
a huge difference in debilitating diseases. The effort you are making to
encourage eating, keeping him clean if urination or defecation becomes
a problem with immobility, making sure of adequate water intake all make
a big difference. And just like people, dogs like to be comforted when
they are ill, most of the time.
I hope that this things have improved by now. In cerebrovascular accidents
improvement usually will occur.
Mike Richards, DVM
Possible Brain Tumor
Q: Hi Dr. Mike, I am writing to you to get a "second
opinion" on my dog who has been diagnosed with a brain tumor. No tests
have been done on her, but my vet says that the symptoms are unmistakable--nystagmus,
head severely cocked to the right, no balance. Here is a little bit more
info: She is 14 years old. Several months ago she had what appeared to
be a seizure, although I now know that it was not a true seizure. She had
been lying on the couch and tried to get up but fell off . She stumbled
around and started panting heavily, but before I even got the vet on the
phone she had recovered. About 2 months ago, it happened again and I brought
her to the vet. By the time the vet saw her, she was fine again. Two days
ago; however, she had a similar episode only this time she seemed to be
going in circles and she had rapid eye movement from side to side. Again
she recovered, but several hours later it happened again and she has not
recovered yet. I took her to the vet yesterday morning and that's when
the vet told me she had a brain tumor and that she had only a matter of
months to live. The vet gave her a shot of cortisone and said it may help
somewhat, but that that if she had not improved within 48 hours, I should
consider euthanasia, as things would only get worse. Its been about 26
hours now and she seems worse. (I did give her a sedative, which the vet
said would help her calm down, but now I wonder if that may be the reason
she actually seems worse). Based on what I've written, can you say with
certainty that she probably does have a brain tumor or is there the possibility
of something else? I do trust the opinion of the vet, but do not want to
have her put to sleep if there is a possibility that it could be something
that is not life-threatening. I realize I could get another opinion from
another local vet, of course, but I also don't want to put her through
a lot of tests. Your opinion would be greatly appreciated.
A: It is definitely possible that your dog may
have a brain tumor. The signs seen would be consistent with some tumor
locations. On the other hand, it is also possible that several other conditions
could lead to the symptoms you are seeing. The most common cause of these
symptoms is idiopathic vestibular syndrome. Most dogs only have one episode
of this condition, which looks exactly like what you are describing. Some
dogs have more than one episode. One dog in our practice had at least 10
episodes over the course of one and half years -- and we did an extensive
work-up to rule out other problems in that dog without finding anything.
I would not rule out this possibility just because of the recurrences.
Inner ear infections can cause the symptoms you are seeing and these are
hard to rule out without taking X-rays (only about 60% of inner ear infections
can be seen on X-rays) or using other diagnostic tests to be certain that
the inner ear is not the problem. Dogs can have cerebrovascular accidents,
"strokes", but they seem to be rare in comparison with other species, especially
people. Dobermans may be predisposed to this problem. Granulometous meningioencephalitis
(GME) can have similar signs to the ones you described. It is a serious
problem and the prognosis for long term survival with GME is poor, too.
Peripheral (idopathic, geriatric) vestibular syndrome will normally
clear up with or without treatment, although a few dogs have lingering
residual effects such as a persistent head tilt and recurrences can happen.
Inner ear infections are treatable in most cases. Most dogs have at least
a good partial recovery from cerebrovascular accidents. I would strongly
advise ruling out these problem prior to considering a drastic measure
like euthanasia. Your vet can refer you to a veterinary neurologist with
the equipment and experience to give you a good second opinion on this
condition, if you wish to pursue a diagnosis. This would involve allowing
some testing and it is possible that the testing could be expensive, especially
if something like an MRI seems necessary after a neurologic exam.
Good luck with this.
Mike Richards, DVM
Last edited 01/30/05
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