Seizures in Dogs

by
,

Seizures in Dogs

Eddies Seizures

A: Doris- Seizures occur for many reasons. There are a number of classification schemes for seizures based on why they occur or what they look like when they do occur. A short explanation of one of those schemes might help to understand what the possibilities are. Seizures can occur for no apparent reason --- and no reason can be found despite careful examination. This type of seizure activity is referred to by some vets as primary epilepsy, or idiopathic epilepsy. Most of the time the onset of seizures in dogs with primary epilepsy is between one and five years of age and there usually is a fairly long interval between the first seizure and subsequent seizures when they occur. While primary epilepsy is common it is not the most likely problem in Eddie's case because he was older when the seizures started and because the interval between seizures was short. Seizures can occur as a reaction to medication, allergies, toxins, other diseases, fevers and anything else that disturbs brain function. These seizures are sometimes referred to as reactive seizures or secondary seizures. It is often possible to figure out the cause of this type of seizure based on the history of another illness known to lead to seizure activity, the clinical signs at the time of seizuring or a known history of using a medication that may lead to seizure activity. Allergies are a lot harder to rule out as a cause of seizures, especially food allergies. It may be worth following an limited antigen diet. This is a diet with one meat source, preferably a meat source that the dog hasn't eaten before, and limited carbohydrate sources, such as just rice or just potatoes. I think that seizures due to allergies probably occur, based on several clinical case reports in the literature, but I think that they are pretty rare. Still, when seizures won't respond to medication it seems reasonable to rule out this possibility. Reactive seizures can occur at any age. A careful review of Eddie's prior medical history to try to rule out exposure to distemper, toxins such as lead, chronically administered medications and other illnesses can be helpful, sometimes, in discerning the cause of seizures. Another cause of seizures is anatomical or structural disease in the brain. This can be from a brain tumor, hydrocephalus (inadequate drainage of fluid in the skull), bleeding in the brain, circulatory problems in the brain and other structural or anatomical problems. Unfortunately, in older dogs (over five years of age) with seizures that occur without a prior history of seizure activity and that recur quickly, the most likely diagnosis is a brain tumor. This means that this possibility is high in Eddie's case. Magnetic resonance imaging (MRI) and computed tomagraphy (CT) scans are very helpful in diagnosing brain tumors. Due to the cost of these procedures it may be a good idea to think about the next step for a brain tumor, which would be radiation therapy or surgery, before spending the money for the scans. If you know that these options are not available or not suitable in Eddie's case, then it may not be worth making a definite diagnosis. A really careful neurologic exam might reveal clues about the possibility of a seizure but most of the time there aren't discernible neurologic signs in dogs with brain tumors, at least early on. The last cause of "seizures" are things that look a lot like seizures, but aren't. The most common problems that are sometimes mistaken for seizures are fainting due to heart disease and low blood sugar (hypoglycemia), which is most commonly associated with overproduction of insulin due to insulinomas (a tumor of the pancreas). I don't think these problems are very likely as it seems like your vet is being cautious about testing for them. Potassium bromide does make a good addition to phenobarbital for seizures that are hard to control. In addition it does seem like some dogs need to be at the high end of the serum levels ( 30 to 40 ug/dl at trough times ) in order to have seizure control. I hope that some of this information is helpful. If I missed anything that you need to know, please write back. Mike Richards, DVM 3/30/99

Seizures and spaying

Q: I have a 3 year old border collie who last December started having seizures - after having testing done it was determined she had an active case of ehrliciosis which was treated and she was immediately started on phenobarbitol. Also, immediately before her first seizure she had a Heartgard Plus tablet and also was put under anesthesia to have her hips OFA'd. My question is...I would like to have her spayed, however I don't want to do anything to cause problems with seizures...the neurologist doesn't want to try to wean her off the phenobarbitol for 6 months from her last seizure which was in February. So I won't know for quite a while if the seizures were brought on by the ehrliciosis or if it is epilepsy. Should I just wait awhile before having her spayed or are my worries about anethesia and seizures unfounded? Any insights you have have would be appreciated.

A: Sue- Sometimes I wonder if I have just been lucky and shouldn't base an answer on clinical experience but here goes: I have anesthetized A LOT of patients who have seizure disorders and a fair number of patients (at least 20 or more) who have seizure disorders and were on phenobarbital at the time of the anesthetic procedure. So far, I can not remember having an anesthetic crisis in one of these patients. We don't use barbituate induction agents anymore and have not had reactions to ketamine/valium induction and isoflurane maintenance. I know other combinations used by other vets successfully, too. So I think that it would be a good idea to go ahead and spay your dog if you wish to. There may even be some benefit since it reduces at least one major stress in her life (estral periods) that may (or may not) lower her seizure threshold. The only problem we have had is that we routinely use acepromazine as a preanesthetic agent and it can lower the seizure threshold. Not all vets believe this happens but I have twice given it to dogs with histories of seizure activity and had seizures occur within a couple of minutes of administering the acepromazine. So now I try really really hard to remember not to give it to patients with a history of seizures. Since it is part of our normal routine, we really do have to pay attention to make sure we don't give it to seizure prone patients. You might want to remind your vet's staff on the day you drop her off that she does have seizures. Since spaying is an elective procedure, you do have the option of waiting, as you point out. At her age (I am assuming she has been in heat at least twice) there is no particular benefit to spaying her before the next heat, except the small possibility that it might reduce the risk of seizures around the time of estrus. Hope this helps in your decision making. If this information leads to further questions, please send them. Mike Richards, DVM 4/17/99

Seizures and Heartworm treatment

Q: Dr. Mike. We recently adopted from the pound a 1 year old chocolate lab/doberman mix to be a playmate for our 7 month old black lab. Upon his initial physical he was tested positive for Heartworms and immediately placed on the Immiticide treatment. He appeared to be doing well through the first three weeks of rest (other than not being thrilled about having to remain rested). During the end of the forth week (just prior to being injected with a dose of heartworm preventative medicine) he started to develop seizures (appearing to be like epilepsy). These seizures would ensue after he would stand up when we were going to bring him out to do his business. They have gotten progressively worse and our vet does not know what to make of it. She says that this had happened with one other dog also and she can't explain it. Have you heard of any such side effect from this medicine. If so are the seizures a temporary side effect that goes away with time. If not how are the seizures treated (ie phenol-barbitol) and what would be the effect on the dogs activity and quality of life. Any help would be appreciated. Brett

A: Brett- We have not seen seizures during the time period after melarsomine (Immiticide Rx) injection. The pattern of the seizures you are seeing suggests that heart disease may be present (fainting from heart problems can look an awful lot like a seizure). I would hope that this problem has resolved. If not, a careful review of the cause and then appropriate treatment is in order. Phenobarbital is the most commonly recommended seizure control medication, if seizure control does prove to be necessary. Mike Richards, DVM

Seizures with vocalization

Q: Dear Dr. Mike, (or whoever) I was reading up on the net about seizures because my dog recently had two within a period of about 3 months and he's never had them before. When people explained their dog's seizures they weren't the same as mine. My dog didn't just move one foot or go unconscious. My dog is a mixed terrier mutt (the best kind), he actually looks like he has some snauzer and shepherd and wolf in him, and he's about ten years old. About a week ago he had his second seizure where he would get restless, fall to the ground paw the air with all feet and let out this horrible sounding wail that puts me into tears. When I described this to my vet over the phone he acted like it was no big deal and said it sounds like he had a seizure. Just keep an eye on him. I'm really scared. Is this something that can occur in dogs as they get older? Does this hurt my dog? Is that why he wails so loudly? Should my vet be running tests on him or should we wait and see if they become more frequent? A lot of changes have occurred in my dog over the past year. He doesn't run or bike with me anymore. We can mention the word walk around him without spelling it because he never wants to go out. He's gained about ten pounds although he eats the same. I cry sometimes because his age is showing. And yet if there is a squirrel or deer or bunny out he will be off in a second so I know he can still run. But these seizures really scare me. Oh yea. They usually only last maybe a minute and then he gets up, shakes himself off and goes back to bed. Any help will be greatly appreciated.

A: I think that it is possible that your dog is having seizure episodes. The exact symptoms can vary from dog to dog quite a bit. The vocalizing worries me, though. While this can occur with seizures it seems to occur more often with syncope (fainting due to heart disease) in our practice. I really think you should insist on a good physical exam and possibly lab work to rule out heart disease and check for treatable reasons that a seizure might have occurred. Mike Richards, DVM

Seizures in Pug

Q: This is the first e-mail I have ever written so please bear with me and my grammer. To get to the point we have a pug, 2years old the end of Sept '97 (the day OJ was acquitted). I bought him from a breeder as a surprise for my sig other. His name is Chilli. He has always been very happy and energetic and has brought nothing but pleasure to us and our 3 yr old son. The Thursday before Labor day Chilli had had what seemed like a cold, runny nose, for a couple of days. We took him to the vet wanting to nip it in the bud. The vet said he had allergies and gave him an inj (probably cortisone). At the same time Chilli was due for his immunizations, so the vet gave them all to him. That evening Chilli threw up. Friday he seemed better although seemed tired. Friday in the middle of the night Chilli woke up yipping and having trouble breathing. Saturday did not look much better, so we decided to keep an eye on him. He rested most of the day but that afternoon seemed a little better (now looking back maybe only in spirit). Sat night was horrible, he yiped twice that night scared to death. Sun morning we woke up to a noise that sounded like Chilli had fallen into the tub. We found him on his side having what seemed to be a seizure, foaming at the mouth, kicking with all fours almost like puppies do when they have dreams, only with much more force and tension. We rushed Chilli to the emergency room. $400 later, his blood work came back normal. The vet put him on prednisone and suggested a spinal tap for meningitis and pug encephalitis. He has had a normal appetite all along, his spirit seems up and down. By thurs after the emergency room, Chilli seemed 500% improved. Sat his stools stared to soften somewhat however we attributed this to his diet up to that point, rice and boiled chicken the recommendation of the vet. Monday (6-9) at 2pm Chilli had another seizure like episode. This was the first day off his prednisone (vet order to start alternating days). This seizure lasted about 30 sec. He had another on about 1030 pm lasting about 1-2 min. We decided to give him the prednisone. 8am Tues morning Chilli had an episode lasting at least 2min, probably towards 3. Since his breathing is labored most of the time, his stools are becoming the consistency of refried mushy beans, he cannot seem to control his bladder at sometime the bowel movements. His body seems to swell at times including his tongue. Chilli's ears and head feel warm. the vet said he did not have a temp. He is eating like a pig, which is what he really has always done, he loves food. He seems like good ol Chilli then he seems so tired and sad. We have made many calls to vets and neighbors with animals for suggestions and insight. No one can seem to help us. The expense of ct scans and spinal taps is out of our reach. But he is our fuzzy person and want him to continue to be a part of our lives. However, if he may be in pain, or have something fatal we feel inhuman not being able to help him. He is lying next to us resting and we try to understand what is happening. Discouraged and torn by empty checkbooks unable to afford testing. The vets do a good job of sending guilt at letting a dog go without, yet they feel no guilt by demanding such high prices to help an animal, on in which they just said they were so dedicated to helping... sadly only at the right price. If this were a human physician, this would not happen. I know you do not need to hear my opinion. Please understand, we seek ways too get information that could lead us in some direction for resolution. Your advice or response would be dearly appreciated. Thank you for listening. We look forward to some response.

A: C- It is not possible to give you much help via email in a situation like this, although there are a few things to consider. The first and most important is that a visit to a veterinary neurologist, even if you can not afford much testing, is likely to be more valuable than an MRI in this situation. If you live in a locality in which it is possible to find a veterinary neurologist (near a veterinary school and in many urban locales) that would be a good idea. A strong possibility is a condition known as pug encephalitis but there are probably over a hundred known causes of seizures so there are quite a few other possibilities. Pug encephalitis is a disease in which seizures and other neurologic signs occur, including circling when walking, blindness and head pressing. The cause of the disease is unknown. It was first discovered in pugs but has been documented in the Maltese as well and probably occurs in more than these two breeds. The cause is unknown and I have not seen much in the way of treatment recommendations, either. It is possible that corticosteroids may help but I am not sure. At present this disorder is considered to be fatal in most cases. Due to the vaccinations being given on the initial day, there has to be consideration of a possible vaccine reaction. In most cases, vaccine reactions are responsive to corticosteroids. There have been reports of encephalitis associated with vaccination but these are not frequent occurrences. Your dog in in the age range in which problems like hepatic blood vessel shunts (porto-systemic shunts) are possible. This is a situation in which the liver is cut off from a large percentage of the blood flow it would normally receive and therefore does not function as well. This often causes signs at an earlier age occasionally will first surface as a problem in young adult dogs. Epileptic seizures do occur in pugs and may not show up until this age. If this is the case, seizure control medications are worth considering and may provide control of the seizures on a long term basis. Sometime after this crisis has past, if you wish to discuss the way in which veterinary health care is managed in comparison to human health care I would be happy to do that with you. It is a tough situation for many pet owners now that extra-ordinarily complex procedures are available for pets, but at a high cost. It was all a lot easier back in the days James Herriot wrote of, when it was possible to look the client in the eye and say in all honesty "we have done all we could". Rarely is it that simple, anymore. I wish you and Chilli the best of luck with this situation. Mike Richards, DVM

Pug puppy with seizures

Q: HI MIKE ,DO YOU KNOW WHY A MALE PUG PUPPY (ABOUT 2MONTHS-3MONTHS OLD) WOULD HAVE SEIZURES? HE HAD A "COLD" ABOUT 2 WEEKS AGO. THANKS, MARY

A: In a puppy this young, particularly a pug, the number one rule out would be hydrocephalus (water on the brain). It is necessary to do an MRI or CT scan to diagnose this definitively. Due to the cost (about $850) most people won't do this for a puppy. Sometimes there are physical signs that make it more likely, like open fontanelles, strabismus (one eye looking in a different direction from the other one) and lethargy or dullness. Sometimes seizures are the only sign. Other causes of seizuring in puppies this young include meningitis/encephalitis problems (like distemper virus infection), liver disorders (especially liver shunts -- circulatory problems with neonatal circulation), intestinal parasites, hypoglycemia and trauma. Birth may be traumatic enough in the short nosed breeds to lead to seizures even if it seemed to go OK. A good physical exam and labwork to rule out systemic or organ disease and intestinal parasites should be done in puppy this young with seizures. If the lab work checks out normally it may be necessary to treat the seizures without firmly establishing the cause. Hope this helps. Mike

Seizuring Pug puppy

Q: Hi! My daughter has a pug puppy who has been having seizures for two months now. He spent a week at Tech and our vet has been conferring regularly with the vets there. There is no definite diagnosis, so he is considered to have epilepsy. He is now 6 months old. The problem is that he is no longer responding to the phenobarbitol. It worked pretty well, except that he would usually experience mild seizure activity on weekends. This past week, he started with the mild activity on Wednesday, and it got progressively worse throughout the weekend (when we were puppy sitting) Even on the medication, he was seizing approximately every hour or every two hours. It also seemed to take him longer to come out of the seizures. His dosage was increased on Friday to 3 tablets a day (32.5 mg.) (he usually takes 2). When he was at Tech, they discovered that his liver processes the phenobarbitol and eliminates it from his system fairly rapidly, hence the high dosage. The blood levels were checked on Saturday and the results will be back on Monday. His medication will probably be amended to include, or totally switched to, potassium bromide. I am concerned that the number and severity of seizures that he has endured will make it more difficult to control them. I am also concerned about brain damage. So far, I don't think his temperature has been elevated (that is what our vet and the emergency vets have said we need to be concerned about) Are they likely to get worse as he ages? Will he ever be able to lead a normal puppy life? He is such a sweetie and it is distressing to see him either doped up or continually woozy from seizures. Thanks for your consideration. Prudence

A: Prudence- The combination of phenobarbital and potassium bromide is considered to be pretty effective by most of the neurologists I have corresponded with. It is important to adjust phenobarbital levels based on the blood levels of the medication rather than by the starting dosage guidelines. Some dogs need significantly higher dosages than the the recommended guidelines for starting therapy. It is also important to monitor both the peak and the trough dosages of phenobarbital (just after the pill and just before the next pill) in order to assess what is happening when the medication is not working well. If potassium bromide has already been started please remember to be patient about its effects. It produces an appearance of drunkenness that lasts a couple of weeks and it takes up to 25 days to achieve stable blood levels so you have to give it some time to work while putting up with its side effects. These usually go away once the dog adjusts. If phenobarbital and potassium bromide don't work well other choices include felbamate, clonazepam and clorazepate for seizure control (usually used in combination with phenobarbital or even with phenobarbital, potassium bromide and one of these choices). It is very difficult to figure out the prognosis in seizure disorders when the underlying cause can not be established. I wish I could help with that aspect of your question but it just doesn't seem possible to do so. The neurologists at Virginia Tech are very good, in my opinion. If there is a way to help I really think they will find it if you keep in contact with them and let them know how things are progressing -- which is also very important to do with your local vet, too! Seizures require a lot of teamwork and a good level of communication between the owner and the veterinarians treating the case when they are not easily controlled. Mike Richards, DVM

Seizures in Dalmatian

Q: Thank you so much for having such a great site. It is Friday evening here and my 3 yr old female Dalmation has just suffered her second seizure today, never having had one before. The information off your site has helped somewhat in calming us by providing some knowledge. I have had 2 other Dals and never this problem. It scared my wife who witnessed the 1st seizure and now me who saw this one. The dog runs with me about 30-40 miles a week. She was limping about 3 weeks ago and the vet gave us some oral cortic steroids for a possibly torn or inflamed tendon. She has been off the med for about 2 weeks now. She also may have eaten some green dog repellant nuggets containing Methyl Nonyl Ketone (XP-20) which we put around some flowerbeds. The seizures lasted 3-4 minutes, with consciousness, frothing of the mouth and loss of bowel and bladder control. She drinks a lot of water normally and conversely urinates frequently so no change seen there. We have also had thunderstorms moving through the area all day. My wife mentioned that tie, what is the significance of storms? She will probably not be able to be seen by the vet until Monday, so as I said your site does provide some insight into possibilities. Can you offer any ideas? Once again, thanks for the sight, May God and St. Francis bless you! j.

A: It might be a good idea to call the National Animal Poison Control Center at 800-548-2423 or 900-680-0000 to check on the potential toxicity of the dog repellent tablets. I can't find anything here to suggest they are toxic, though. The NAPCC does charge for calls. Seizures are not that unusual in dogs but it is a really good idea to have your dalmatian checked by your vet to rule out other problems and see if a treatable condition may be leading to the seizures. As long as they aren't continuing there is probably no great rush. Monday should be fine. Thunderstorms seem to initiate seizure activity in a lot of dogs. I think this is because the adrenal hormones released in fearful situations may lower the seizure threshold. I am not sure that is the actual reason this happens -- just conjecturing. In this case, there is a seizure disorder already present but seizures happen more easily due to the external stimulus. Your vet can probably tell you more about all of this on Monday. Mike Richards, DVM

Dalmatian with seizures - continued

Q: Howdy again Dr Mike! I wrote you a few weeks ago about my Dalamation and seizures she suffered. Her blood work was normal except for possibly a little anemia which may have been due to the small sample. I believe this because she eats well and has plenty of energy. We were not aware of her having had any other seizures since those 2 and I think we would know because we have a patio home and would notice if she lost bladder or bowel control. Since the first seizures I started her off running again because she loves it. We overdid it one day and she was limping a little so I put her back on the non-imflammatories (Rimadyl)for awhile but she quit limping so took her off them about a week or more ago. The most recent seizures were Friday around midnight then she evidently had one Saturday afternoon while we were out too. None since. My wife thinks they might be convulsions instead of seizures, I don't know what that means, what is the difference? She thinks it could be some plant the dog is eating. She eats a lot of grass when we run, so when we don't she substitutes herbs such as sage, basil, pepper plants or whatever. She usually hurls the sage but the others agree with her. My wife got her some sort of ground up Barley to add to her food to hopefully replace the herbs and grass. My wife is also suspecting her food. She eats Nutro Max and has for about a year with no problems and the seizures occurred with different sacks. I am considering putting her back on ProPlan Chicken after this. She (my wife) doesn't see why all of a sudden at 3 yrs of age these seizures would come on. Any ideas? Thanks again for your great site and information.

A: Most people use the terms seizure and convulsion interchangeably but it is probably more accurate to say that the seizure is the brain activity that leads to the physical symptom of convulsing. Convulsions can occur as the result of toxins and there have been reports of them occurring due to allergies in people. I am not sure if this has been documented in dogs. If there is a problem with food or with the stuff your dog eats on her runs, allergy to a plant or a particular ingredient of the dog food is the most likely problem. In this case, changing foods will only help if the offending ingredient (like beef, chicken, food coloring, etc.) is not found in the new food. It isn't unusual at all for primary epilepsy (seizures for no discernible cause) to begin as late as 3 years of age or even later. However, it is always good to maintain a high degree of suspicion that there is a discoverable cause of the seizure activity. To help in your thought processes, here is a list of some causes of seizures: trauma -- even if it happened a long time ago, primary epilepsy, infectious diseases, shunts in the liver circulatory system, low blood calcium levels, low blood sugar levels, high blood sugar levels (diabetes), kidney damage, toxic substances (antifreeze, lead, insecticides and strychnine are the ones we have seen causing seizure activity), liver failure and possibly hormonal disorders such as Cushing's disease and hypothyroidism. There are also things that people sometimes mistake for seizures. These are heart disease causing fainting, sleep disorders (narcolepsy), peripheral vestibular syndrome, inapparent sources of pain leading to odd behaviors, muscle tremor disorders and obsessive/compulsive disorders that lead to repeated behavior patterns. It can be reassuring to get a second opinion from a veterinary neurologist when dealing with seizure disorders. Most of the time they won't find anything your general practitioner vet didn't find but that is still reassuring. Your vet will probably know of a specialist reasonably close to you if you want to discuss this with someone who sees a lot of seizuring dogs. Mike Richards, DVM

Seizures and medication - Dalmatian

Q: Dr. Mike: Our three year old Dalmatian, Pepper, had his first cluster seisure(3 seizures within a 24 hour period) when he was one and half years old. After a battery of tests (blood and liver etc) which all turned out normal, our vet started Pepper on a low dosage of Phenobarbital. But he was still experiencing cluster seizures on a monthly basis. With each episode, our vet would gradually increase Pepper's Phenobarbital dosage. Today his dosage is 150mg twice a day which the vet says is the maximum safe dosage for a dog his size, 70 pounds. We noticed that with each episode, Pepper became less responsive to commands as if he had never learned them! And this behavior seems permanent. Could this be the result of Phenobarbital or could he be suffering from some mild form of brain damage? In addition to Phenobarbital, our vet recently prescribed KBr after a major seizure episode which lasted 5 llllong minutes. KBr is an experimental drug for seizure control and the vet does not seem very knowledgeable about this drug. Can you provide us with some information? Since taking this medication, Pepper seems to have lost his sense of balance and coordination. He bumps into doors, walls, fences... sometimes he simply falls while walking. Are these side effects normal? Please help, my husband and I are going crazy not knowing what to expect from this drug. Thank you for your help. BJ

A: It is disheartening when seizure medications don't work well. I can not tell from your letter if this has been done, but checking the blood level of the phenobarbital is often the most reliable way to determine if effective levels are being reached in the bloodstream. Some dogs do require more phenobarbital than the maximum recommended dosages in order to achieve sufficient blood levels. If the phenobarbital blood levels are not within the therapeutic range, increasing it is OK. Seizures may not be controlled even if the phenobarbital level is in the range in which it normally would work. Potassium bromide (KBr) is the medication most commonly used to supplement the effect of phenobarbital in that case. When you first put your dog on the KBr you will see almost all the things that first happened with phenobarbital -- the "drunken" appearance, falling, running into things, etc. This can go on for about 3 weeks and then the dog adjusts to the dosage. It is an effective combination and once your dog adjusts it doesn't seem to depress overall personality traits much. It is possible that your dog may have brain damage, since that is one of the causes of seizures. It is probably more likely that the medications are causing the problems you are currently seeing, though. Mike Richards, DVM

Seizure in 3 year old Male Akita

Q: First let me comment that providing this Q&A service is very much appreciated. Thank you. Our Akita, Storm, is a 3 y/o male - who was in perfect health until he acquired an ear infection last October. After PO antibiotics failed, he was put under general anesthesia to examine and clean the ear. Acepromazine and Droperidol were used in the GA. This was on 9/1/96. After returning home, he acted very strangely. Initially this was attributed to the Droperidol / stress of procedure. Aprox. 36 hours after the procedure he had a generalized tonic-clonic seizure that lasted for 2-3 minutes (just short of a lifetime for us observing). He had loss of bladder, convulsive movements of all 4 legs, was non-responsive, heavy drooling, clenched mouth (fortunately not on the tongue). He recovered "miraculously" soon after. After some discussion (and 2 weeks of no seizure activity) the Vet felt that he was "borderline epileptic" - and the Acepromazine probably triggered the episode. His advice was to simply monitor him. We were given 10 mg Valium to give him PO if we felt he was going to have a seizure. On 3/1/97 (6 months to the day) - he again had a seizure with the same duration and symptoms. No Vet visits to associate this one with, however he had caught / eaten a bird the day before and had several episodes of vomiting. The Vet re-affirmed that be was "borderline epileptic" - and in fact said that many of his epileptic dogs had seized the prior night (major thunder/rain storm). The Vet's advice was unchanged. Both of these episodes happened at ~2:30 am, for what it's worth. 3 days later - he was definitely acting strangely - licking all areas of the floor, wall, running around the room in a generally hyper state (he is normally very dignified/stately). We gave him the Valium - but felt a seizure was imminent. He did not seize (at least not a TC episode). I suppose one question I have is whether his extremely strange actions was prodromal or perhaps a temporal lobe type seizure. Perhaps then progressing (or not) on to a TC state. Do temporal lobe seizure in dogs result in bizarre activity such as this? He is fairly large (~120, 29") and we are somewhat concerned about him damaging himself during a seizure "fall" and of course the concern of biting his tongue (out Vet said that tongue swallowing is not a problem). Add to that a major dose of [overly] concerned "parents" - and the question of anti-seizure meds is foremost in our minds. Are these episodes too few / short / severe to warrant prophylactic Rx? How "safe" are seizures (what concerns should we have about damage from them)? To add to a note already too long - a breeder told us that since Valium actually causes some Akitas to get hyper - that in those dogs it is not effective as an anti-convulsant. Is this correct? To finish the picture, we also have a 2 y/o spayed female Akita. Any general advice would also be appreciated. Thank you for your time.

A: I will try to cover everything you asked but if I miss something, feel free to write again. Acepromazine does seem to lower the seizure threshold in some animals and can apparently allow a seizure to occur that might not have without the lowering of the seizure threshold. Paradoxically, it can raise the seizure threshold associated with some anesthetic agents (most notably ketamine). I know almost nothing about Droperidol and do not know if it can promote seizures or have any effect on a dog already prone to them. Diazepam (Valium Rx) is helpful in reducing seizure activity in most dogs but it does have a paradoxical excitatory effect in a few animals. I don't know if this stimulates seizure activity but it does occur. I can't answer the question about the temporal lobe seizure activity, either. Dogs definitely have a wide variation in seizure activity but it is hard to say whether seizures which might not cause recognizable clinical signs occur because it is so hard to judge the mental state of the dog. I assume that almost any type of seizure possible in a human probably occurs in dogs as well, though. When to medicate to control seizure activity is a really debatable question. The pro treatment side of the argument for early treatment is that "mirroring" and "kindling" of seizures are recognized in dogs. Mirroring is when an area of the brain causing seizures on one side induces the development of an area causing seizures in the same place in the other half of the brain. Kindling is the process in which seizures make it easier for other seizures to occur -- in effect lowering the seizure threshold a little bit every time one happens. The con side of the argument mostly revolves around the side effects of the most consistently successful seizure control medication in dogs, phenobarbital. It can cause incoordination and a general lethargy for several weeks on first administration. Most dogs overcome these effects in a few weeks, though. It also causes increased hunger, often increased water consumption and therefore urination and it causes severe liver damage in some patients. Not many, but enough to be very worrisome. Primidone (Rx) is commonly used in dogs to avoid keeping controlled substances on hand but it is more likely to be toxic to the liver and is not a good first choice for seizure control. Seizures themselves are very unlikely to kill a dog, but it does sometimes happen as well. So the question is, when are the seizures severe enough or frequent enough to absolutely warrant treatment? I think we work out a different answer in almost every case. We try to make our best guess as to what is best for each individual patient. The traditional guidelines in veterinary medicine have been seizures that last for longer than 5 minutes (actual seizure activity) or seizures that are occurring more than once a month. We probably stick reasonably close to these guidelines but are a little quicker to consider seizure medications now that there is pretty good evidence for the kindling theory. Once it seems pretty apparent that the seizures are going to continue to get closer and closer we sometimes treat now even if they are till more than a month apart. Hope this helps. Mike Richards, DVM

Seizures and weight loss in Lab

Q: Hi Dr Mike, I have a male labrador 4 years old. For over a years he has dropped down on the ground in some kind of seizure about once a month. Our veterinary can not give us a diagnose. About a month ago we started medication (Mysoline 250 mg - 4 pills a day). Since then he has had no attack, but he doesn´t seem to be all right. The dog has lost a lot of weight the last 6 months. He walks more slowly, but he also sometimes plays with our other dogs. We do not have veterinaries with magnetic equipment, just old x-ray-machines. Now we are worried that the dog is also in pain. Please could you give us some advice on what to do? Kind regards A: It can be pretty hard to pinpoint the cause of seizures, even with magnetic resonance imaging and other advanced diagnostic equipment. I have the luxury of being able to refer to specialists with this equipment but it is still too expensive for a lot of my clients to take advantage of them. The weight loss is awfully worrisome. It seems like it would be a really good idea to check for some sort of systemic disease (liver, heart or kidney problems for instance). Heart problems usually show on a physical exam and the other problems can be detected with blood work. Your vets have probably already done that, though. Still, rechecking those values after using primidone (Mysoline) is not a bad idea, anyway. I prefer phenobarbital to primidone for seizure control since it has less side effects but lots of vets use primidone. That is probably a minor point. Pain does not seem to be a big problem with seizures in dogs, at least between seizure episodes -- is there some reason you suspect this? I wish I could offer advice that might be really useful but I can't . Mike Richards, DVM

Strange seizures

Q: Our dog has strange seizures that neither our local vet nor a specialist (internist) could diagnose. The dog's problems begin with rapid eye motion from side to side. He appears disoriented. In severe cases, he then slumps to the ground. Blood tests have been negative. After an episode the dog is fine, but perhaps weak. No other symptoms, no behavior changes. Episodes are multiple times per day. Dog seems to retain consciousness through all episodes. Would some specialized blood tests help?? Would you recommend an MRI?? Any ideas would be much appreciated.

A: I have looked up causes of nystagmus (the rapid eye motion) and there are a number of possible causes of this behavior but most don't occur in conjunction with seizures. If you can provide a little more information, such as the age and breed of your dog, it might help in narrowing down the possible diagnoses. As a general answer, I do think an MRI might be helpful, especially if it is done at a veterinary teaching hospital or referral center where a veterinary neurologist is available to assess it in combination with a neurologic examination of your dog. Finding a specific brain disorder is not always helpful but if you are willing to pursue treatment options such as surgery or radiation therapy for tumors if they are present, it may be. Good luck with this. Mike Richards, DVM

More on this problem:

Q: My husband wrote to you this afternoon; I am writing because I know a lot more facts, hope the duplication is not an inconvenience. We have an 8-year old, Chow/Akita/Australian Shepherd named Sinbad. Up until mid-December, he seemed fine. He was savagely attacked by a 125 pound Akita and well stitched up by his vet. In mid-January, we decided he had been pretty lethargic and it would be a good time to find him some female companionship. A 5 1/2 month old Samoyed pup came to live with us - he accepted her immediately. She played with him very hard and would throw all of her 40 pounds at him in fun. We noticed that he seemed to "freeze" on his walks, nearly immediately. After a week, he was experiencing nystagmus, his eyes moving back and forth, his head following and often his rump falling to the ground. We kept the pup another week and these episodes continued, as many as 5 or 6 a day. Our vet (who didn't see him seize) immediately diagnosed epilepsy (Sinbad had had a single grand mal seizure 5 years ago) and put him on Phenobarbitol; then we had a stoned seizing dog. Blood work was excellent. His spells just didn't seem like epilepsy in that Sinbad does retain consciousness each and every time. I called the vet assn. in Seattle who recommended a specialist in internal medicine. We saw him a week ago and he confirmed we were not dealing with epilepsy, rather vertigo from an unknown cause and recommended we give him 1/2 a seasickness patch I had in my medicine cabinet. He took his blood pressure and ruled out heart trouble. Following the departure of the wild puppy, Sinbad has been quiet, resting, but his spells continue. There often is stress involved (a barking dog, traffic) but often there is none. After approximately two minutes of rhythmic eye movement and loss of balance, he seems pretty OK, with only residual weakness (he will fall or hop around as his hikes his leg). Sometimes, his pupils will be quite dilated. Our internal medicine specialist recommended we discontinue the Phenobarbitol and "wait and see." He was stumped as to why these spells began although recognized that they coinsided with the stress of the addition of a wild pup in the house; he felt that this was a rare condition principally because Sinbad acts quite normally following these spells. Incidentally, like the pekinese skipperke mix mentioned on your site, Sinbad will wag his tail during his episodes, and will continue to bark despite loosing his balance and toppling over. Do you have any idea of his diagnosis? Should we drive the 6 hours to the vet school to get him tested? Do we need a neurologist? Are there any drugs other than an out of date patch on the ear? Thanks so much.

A: This is a list of possible problems that I can think of that could potentially produce the symptoms you are seeing. Some of this list is very unlikely to cause only the symptoms you are seeing but it helps me to make a big list and then eliminate stuff from it, based on lab tests or as much common sense as I can muster (my staff is convinced that they represent the sole source of common sense available to me at a times). Lack of oxygen to the areas of the brain controlling balance. This could happen because of traumatic injury to the region, blood vessel damage or blood clotting. It can also happen from things like carbon monoxide poisoning but that is probably not too likely with the chronicity of the symptoms. Lack of glucose getting to the areas of the brain controlling balance. This isn't all that unlikely in an older dog but I think hypoglycemia is more common in females. Increase in any metabolic toxin (kidney failure, liver failure, electrolyte imbalances). Increase or decrease in necessary metabolic hormones -- too much adrenal hormones (Cushing's disease) or too little (Addison's disease). Too much thyroid hormone (this is almost always due to excessive administration of the hormone in dogs) or too little (hypothyroidism). Toxins that affect the brain. Lead, other heavy metals, ethylene glycol (anti-freeze), fungal toxins and insecticides. Most of the time, people know that exposure to these is possible and there are usually lots of other signs, but lead can lead can be deceptive and fungal toxins (mycotoxins) are probably rare but would also be hard to know about. Peripheral vestibular syndrome (also known as geriatric vestibular syndrome and idiopathic vestibular syndrome and also often mistakenly referred to as a "stroke"). This syndrome occurs in any age dog but more commonly in older dogs. It has exactly the signs you are seeing but it is not usually episodic. It normally occurs suddenly and then takes a few days to a few weeks to disappear. However, we have seen a syndrome almost identical to what you are describing in a German Shorthair Pointer who did eventually recover completely, as far as we could tell. Almost all dogs do recover from this condition without treatment. Brain tumors. There is a saying "cancer does what it wants". Almost any neurologic symptom is possible with brain tumors. Granulometous meningioencphalitis (GME) is the last thing I can think of. This is a poorly understood (at least by me) nervous system disorder that leads to lots of bizarre neurologic signs, including nystagmus and episodes of balance loss or seizure activity. I know of no sure way to diagnose this disease in a living dog but making sure nothing else is causing the problems and then a good evaluation by someone familiar with the disease is helpful (i.e. -- a veterinary neurologist). I know that is a long list but it may explain why your vet and the internal medicine specialist are not able to provide a definite diagnosis. Whether or not to go further with diagnosis depends on several factors. Eliminating all the easy diagnoses is possible through routine labwork and minimal specialized testing. It might be a little expensive but your vet can do all the necessary testing. Peripheral vestibular disease should clear up in a few weeks. If it doesn't, that leaves the things like brain tumors and GME. The question would then come down to whether or not you would consider brain surgery if that seemed possible. If so, going to a neurology specialist is definitely worthwhile. If not, there is less need unless you just have to know what is happening. I usually find myself needing to know as much as I can when I am trying to deal with difficult situations involving my pets but not everyone feels that way. Hope this helps. Mike Richards, DVM

Seizure - what next

Q: My Staffordshire Terrier or "pit" bull, a 2 1/2 year old male, has experienced asthmatic-like attacks since he was a very young puppy. We have discussed the condition with our Vet and she has tested Timber, but tests have been inconclusive, to my knowledge, as to the exact cause of the attacks. Of course, all of his shots and heartworm treatments are current. When the attacks occur, approximately every 60-90 days or more, he continuously wheezes and breathes heavily for 2-3 minutes, almost seeming not to to be able to catch his breath until the condition gradually subsides. Today, however, something new and more serious occurred. Upon awakening, Timber greeted my wife, who was descending the staircase, whereupon he suddenly slumped to the floor, writhing and erupting into what we assume was some sort of major seizure. He convulsed and foamed at the mouth and his legs continued to move, as though he was trying to run. During the seizure, which seemed to last a good 3-4 minutes, his eyes became very large and seemed to bulge. Also, I think I detected a minute trace of blood in his saliva (possibly a result of biting his tongue?). He did not loose control of his bladder or stool functions. Lastly, a very strong odor accompanied this attack, seemingly emanating from either his mouth or skin. While it occurred, we held and consoled him, not knowing what else to do. Following the seizure, he walked around somewhat disoriented and whined, as though he was looking for a favorite toy or chew. My wife phoned the vet who suggested that it might have been something akin to an epileptic seizure in a human and suggested that a blood test might be in order, as well as medication such as phenobarbitol to increase his threshold to seizure. Do you think the earlier attacks were related to today's much more serious and seemingly lengthier seizure? Are the seizures likely to begin occurring at more regular intervals and will they be life threatening, in and of themselves? What can we do to help and comfort him when they occur? As we are not always home during the day, I am very concerned that a future attack will occur while we're out and that it could be life threatening. We love this kind and gentle "pit" and his loss to a potentially treatable disease would be devastating. Any insight into this problem and your recommendations for appropriate treatment are greatly appreciated.

A: I don't think that the conditions you are describing are related. Dogs very frequently exhibit the respiratory signs you saw previously. This condition affects all dog breeds, but especially the short-nosed breeds. Most of the time, it is hard to find a cause for the attacks and only very rarely does any major problem stem from them. Seizures are much more serious. I have had several patients who only had one seizure in their whole life. Due to this, many vets (including me at times) don't pursue labwork or diagnostics after the first seizure. Lately, I have decided that this is not the best policy. Even though most of the time we find nothing on labwork or physical exam that explains the cause of a seizure, when we do find the cause it can be very important to treat it early. For a couple of years now, I have been advising my clients to allow us to do a really good lab workup for seizure activity the first time seizures are seen. I think it has really benefited two or three patients in the last couple of years who had underlying conditions we were able to recognize and treat early. I am a more hesitant to start phenobarbital therapy on the first seizure. This is a medication with a number of side effects and I like to be sure that there will be more than one seizure before starting a lifelong medication that can cause problems itself. I feel this way even though some research suggests that allowing seizures to continue can make it even easier for them to occur in the future and that in some dogs a "mirroring' effect occurs in which seizure activity generated on one side of the brain will be duplicated on the other side after several seizures. I can understand why some vets go to seizure medications quickly. We use them much more quickly than we did in the past. But I still like to wait and see what will happen after the first one, unless we find a cause in the labwork which makes it pretty certain they will continue to occur. So I'd advise asking your vet about doing an exam, some bloodwork and possibly other labwork if it seems necessary after the initial workup. Most of the time, you'll find out your dog has no obvious cause for the seizure. But once in a while, a treatable underlying condition will surface, such as diabetes, hypoglycemia, liver or kidney disease, etc. 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...

 

Comments