Brain Tumors in Dogs


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


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...