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A New Treatment for Canine Idiopathic Epilepsy: Pexion

A New Treatment for Canine Idiopathic Epilepsy: Pexion

We recently wrote about canine idiopathic epilepsy, a form of epilepsy where the cause remains unknown. Today we are looking at a new treatment; Pexion.

The severity of epilepsy can vary greatly between individual sufferers. Some dogs may experience a single, isolated seizure, whilst other can experience multiple seizures every week.

Recently Boehringer Ingelheim has announced their latest product for the treatment of canine epilepsy, Pexion® (Pexion) an alternative to the traditional phenobarbital or potassium bromide treatments given to epileptic dogs.

Are you using Pexion?

If you’re dog has been prescribed Pexion, let us know how your dog is getting on in the comments below. Join the discussion on how other dog owners are getting on with Pexion and keep the community updated with your progress. 

What Is Pexion?

Unlike other treatments for canine epilepsy, Pexion contains the active ingredient Imepitoin. Imepitoin acts in a similar manner to previous anti-epileptic medicines, potassium bromide and phenobarbital, in that it works to suppress electrical activity in the brain.

Imepitoin partially activates GABA receptors, which are responsible for reducing electrical activity between nerve cells. This partial activation of the GABA receptors is believed to reduce electrical activity and help prevent seizures. Specifically, Imepitoin also has a weak blocking effect on calcium channels that allow electrical signals to be propagated along nerve cells.

See here for more information about Pexion 

Does Pexion Work?

A study conducted on Pexion during its development compared it to the traditional anti-epileptic medicine phenobarbital. A 20 week study of 226 dogs taking the medications found Pexion matched phenobarbital in efficacy, reducing the occurence of seizures by around 50%. 1

Is Pexion a Better Alternative?

The Pexion study showed that it had an effectiveness equivalent to phenobarbital, however, Pexion may be considered a better alternative as it has less severe side effects.

Unlike phenobarbital, Pexion does not pose a hepatotoxicity risk (liver toxicity). This means the regular testing required to ensure that a dog’s liver remains healthy is not needed whilst being given Pexion.

Treating the Epileptic Dog

It is commonly cited that around 0.5 to 5% of dogs suffer from some form of epilepsy, the severity varying between breeds and individuals. In dogs where seizures occur infrequently  owners may consider not using any medication at all, avoiding the side effects associated with anti-epileptic medications.

In dogs where seizures occur more freqently, such as once a month or more, treatment should be considered.

The introduction of Pexion gives owners and vets a greater choice when it comes to treatment, but does not replace phenobarbital and potassium bromide.

Owners should consult their vet and explore all the possibilities when dealing with an epileptic dog.

Seizure Types That Require Immediate Veterinary Assistance

Cluster seizures – When multiple seizures occur in one 24 hour period
Status epilepticus – A persistent epileptic state that lasts for longer than 5 minutes

For more information about epilepsy, such as the causes, what to do during a seizure and more, see this article.

Disclaimer: This article was written as a response to the release of Pexion and as a follow up to a previous article concerning idiopathic epilepsy. I am not affiliated with the product (Pexion) or the manufacturer (Boehringer). 

Image Credit: Onkel_wart

About James Watts

BSc Bioveterinary Science. Editor of PetSci. When I'm not writing, learning, discussing, or reading about animals, you know it's the weekend!


  1. I have now stopped Pexion and put Ziggy on Epiphen. Since we stopped it he hasn’t had a single seizure so far(5 days).The effect of Pexion was horrendous as the fits increased every time we increased it, culminating in 4 seizures in 12 hrs even after rectal valium. He also became more paranoid and jumpy with each increase.Before he started on Pexion he only has single seizures, but as soon as he was on Pexion he started having clusters of 2 seizures every time. I also heard of a lady last week who ended up having her dog put to sleep because it had 30 seizures in a day on Pexion. One thing I would say to everyone who’s dog is on Pexion is, if the seizures get too bad just stop giving it (you can do that with Pexion) and the seizures will reduce straight away. I know of only a couple of dogs who Pexion has worked for. Don’t be afraid to stop it. I just knew if I didn’t stop it after the 4 seizures he might go into status.

    • Dear Faye,
      I posted last week recommending that when changing medication you do it slowly, even pexion. My dog Izzy had 30 seizures a day after stopping the pexion and not having other meds in her system. She had the 30 seizures twice about a week apart and both times the vets had to keep her over night and sedated her. After the second time the vets couldn’t control the seizures and she was put to sleep. Good luck with your dog, hope you never have to make that next step.

      • Sorry Amanda but you are wrong. .you can just stop pexion overnight. ..I did that too and saved my dogs life I believe. ..It even states it in the pexion information that it needs no withdrawal

        • Dear Alison
          All dogs are different and 3 dogs mine included have passed away as a result of stopping pexion and not having something else in place. Thats why you should take your vets advice as they take into account each animals health and age. I repeat, every dog is different and one method worked across the board it would make matters easy for all involved.
          Whatever works best for your dog is best for you. Wishing luck always as epilepsy is the most horrific illness to witness.
          Amanda x

          • One think I know for sure is that each dog reacts differently to anti epileptics and most vets believe it’s through trial and error to find what works best for your dog. It certainly needs lot of patience, time and luck…

    • Hi Faye

      My dog Dillon was on epiphen for 2 years (max dose 240mg per day) at first on epiphen he looked as if he was drunk he could hardly stand, this stopped after 2 weeks and he has only had 2 seizures since, but epiphen can effect the liver, which it did. He needed blood tests regularly then it became monthly, 2 hours before and after food to test his levels. We moved him to pexion (weaning him off epiphen, which will take 3 months) because his liver could have failed . He was put on pexion because it says it does not effect the liver and he has been on it ( 400mg per day) for 2 weeks, his initial wobbly legs have stopped, he does seem to drink more (but epiphen also made him drink a lot)

      Dillon never had many seizures but on seizing he was always alert to his surroundings, I just held him till they passed. He has only had 1 cluster in 4 years ( this is why he was put on epiphen.)

      I hope epiphen works for you , but please have his blood tested and look for the signs off liver problems, goog luck.

  2. Amanda, I think you were just unfortunate when stopping the Pexion that there were so many fits. I know several people who have just stopped Pexion with no ill effects, like myself, so generally speaking it is ok to just stop Pexion as it is not an addictive drug like the other AED’s. Also the info on Pexion says you can just stop it, but I guess like everything there are exceptions and I think unfortunately your dog was one of those, so sorry. Faye x

  3. Yes, sorry Amanda I agree with Faye, I think that you were just unfortunate… the drug Pexion does not react to being stopped suddenly as it does not stay in the system, that is why they state that there is no withdrawal, aside from that I would NEVER EVER recommend using this drug, it almost made me come to the decision to have my boy PTS until I saw this forum and saw what others were also suffering, I am so sorry for your loss x

    • As we have all agreed, each dog reacts differently to each medicine and it is only by trial an error that we may find something that helps our dog. I would not put my dog on any medicine if she/he was having less than 3 fits a month, manage the fits with natural remedies as I did with Izzy. Good luck to everyone on this site I wish you all the best of luck, love and strength.
      Amanda x

  4. My JRT, Trooper, has now been on Pexion for 6 months. He has fewer side effects than on phenobarbitol and we don’t have to put him through the regular blood tests.
    Pexion works for him, he has fewer seizures, 6 weeks between the last 2 rather than 3 weeks with pheno.
    He has put on little weight and he’s no longer as keen to go on walks, he’d rather stay home, but apart from that, he’s very much the same old dog…. It seems experience vary to great degree with regards Pexion, but for Trooper, it works!

  5. My four year old Rhodesian Ridgeback commenced with seizures 7 months ago, he was prescribed Pexion. Seizures continued once every three weeks or so until a massive 8 seizures in one evening resulting in our taking him to the Vet Hospital to see a specialist,
    we nearly lost him, he is now on epiphen and is back to his pre-seizure self.

    He had an MRI scan and spinal tap to get to this stage , I would suggest that everyone considers the advise of a specialist before embarking on any drugs. I know that different dogs react to different things but do not accept that on- going seizures are a fact of life for your dog – they deserve the best….

    • Hi Annemarie

      How did you get your dog off the Pexion? Was it gradually or immediate? What sort of dose was he on? Did you wait until epiphen levels were at a certain level? Sorry for all the questions, I’m desperate to get my dog off Pexion (he’s on epihen as well now) but every time I try to reduce the Pexion, even really slightly, he starts fitting. I’m so scared it’ll be too late soon. Any insight you can give would be massively welcome
      Thanks, Natalie

      • Hi Natalie
        You do not need to wean off Pexion you can just stop giving it, thank goodness. That is what I did with my dog and I know others that have done that too, it states it in their literature that there is no weaning needed. I doubt that the reduction in the Pexion is causing the increased seizures, maybe the pb levels need checking? Good luck and kind regards, Alison

        • Hi Alison
          Thanks for the reply. I know the literature states there’s no weaning off, that’s what’s so frustrating. His pb levels are within therapeutic range (24.4 two weeks ago) but the specialist says we still can’t continue with the Pexion reduction because of the frequency/severity of the seizures etc. They say next step will have to be upping the pb again to aim for a level of about 30 and also bringing in Kbr, waiting until Kbr levels are high enough and THEN attempting another reduction in Pexion, which will be at least another 2-3 months down the line apparently.

          It’s so maddening because my gut instinct is that it’s the Pexion that’s complicating/increasing seizures. Still, it’s heartening to see that you and others have managed to get off the Pexion and are having much better situations for their dogs. Quick question, was your dog on Pexion as a first (and mono) drug and then you switched to pb or had he been on any other drugs before Pexion? Wishing you all the very best, Natalie

          • Hi Natalie
            After going through 3 months of hell with Pexion I think your gut instinct is boy was already on pheno and potassium bromide although we did start to reduce the pheno when he was on the Pexion… they kept telling me to up the dose of Pexion more and more until it reached the max, my dog was not my dog any more and was some phycotic crazy animal.. after continued seizures 3 days running I took the decision myself to just stop the Pexion, was the best decision I ever Ummed and arrhed over, I couldn’t have taken another couple of months of what we had at the time..why not up the pb a little and stop the pexion after 2 weeks and see what happens? The pb will be in the system by then and if needs be you could adjust or add another aed? Just a thought… good luck! xx

          • Thanks Alison, your thoughts are good ones and I think that’s kind of the route I was considering. Am going to speak to the neurologist today and see what sort of increase of the pb to look at, wait a couple weeks and just start reducing the Pexion again and see where we are. Am really pleased you had such a good outcome, everything crossed it carries on well for you and your boy xx

      • If you ask your vet about the valium protocol, it’s basically using the pessaries and tablets then try reducing the pexion half a tablet each week. Look back on this comments list. You can also go on for more information, buy do it slowly with your vets help. Good luck, love Amanda. Xx

        • Hi Amanda
          Thanks very much for this – I didn’t know about the valium protocol. I’ll speak to the specialist/vet in the morning and see if this is something we could get going on asap. I’ll have a look at the site too – many thanks, Natalie xx

        • Can I just say that the valium protocol is used solely for when your dog has a seizure (not always pessaries, we have liquid valium for rectal use) it has nothing to do with the use of Pexion or any other aed. You do not need to wean off Pexion, it even states that in their literature.. I stopped overnight and had immediate positive effects and know of many others that have done the same thing… take a look at the facebook page canine epilepsy, there are a few of us on there that have done just that x

  6. My 7 YO dog started fitting in Jan 2014, started on Pexion 400mg, fitted again, increased to 500mg, fitted again, so this week and upped to 700mg. Waiting to see if he is stabalised. He has side effects of excessive hunger, thirst, slightly ataxic on back legs and much more sleepy in the evening. Hoping the side effects reduce and the frequency stops.

  7. My dog has been on Pexion since August. He had a fit as we swapped from bromide to Pexion the nothing until January of this year. He then had another fit mid February and another 9 days later. My vet suggested upping his Pexion to 600mg in the morning and 400mg in the evening, he did have 400mg morning and night. Hopefully this will stop the fits again.

    • elizabeth hilton

      Hello wendy,

      My collie is 13 and has been on pexion 600mg since august. I took her to the vet yesterday for a six month check up and she was very pleased with her. I suggested weaning Maddie off the pexion, but the vet did not advise that. Maddie has had very few fits since being on pexion, she does not drink so much and only side effect I can detect is she is more agitated and has tremor in front leg. She still chases balls and has 6 mile walks every day. Maddie does not need regular blood tests as pexion doesn’t involve the liver, but oddly there are only 4 dogs on this drug in the whole practice. Most are still on bromide/phenobarb. I know pexion is still a very new drug and many vets are still wary of it and its possible side effects. Good luck to all of you who have tried it on your pets.


      • Murphy has obviously had another fit whilst I was at work today. That’s 3 now in the last month. He only had two all last year. Not sure what to do now! I’m just waiting to hear back from the vet to see whether to up his meds again.

  8. Someone has just told me that Pexion has to be given exactly 12 hours apart, is this the case. I’ve been giving it to Murphy about 13/14 hours apart for the whole time he’s been on it. I was just told twice a day on an empty stomach so he has it an hour before food.

    • Hi our beagle snoopy is on pexion he has half a tablet morn an eve approximately 13/14 hours apart or sometimes even longer depending on when we r home from work etc… Also he has his after he has his breakfast as we weren’t told otherwise…. We were just advised to try and keep as regular as possible ….. Hope Murphy is ok xx

      • Going through a bit of a bad patch with fits at the moment, he has had four so far this year, the last three have each been about two weeks apart. Just trying to work out why. I know this is nothing for some people, but I don’t know what has made him fit like this.

        We’ve upped his dose to 600mg twice a day. Fingers crossed this will work for him. He was doing so well, he only had two fits all last year.

  9. Hi there
    My dog blue has been on pexion for 10.days now when he first started he was on
    400mg in the morning and 400mg at night I gave him first dose at 9pm at 1am he
    Got up for toilet and could not walk he kept falling over as if he was drunk this
    Continued till 7am I phoned vets at 9am to tell him he halfed the dose right away
    He has just had another fit. I am not conviced so far by this drug as he is very sleepy and keeps walking into things also ticked his pupils are very large. And the thirst and
    Hunger is terrible. He is also on epilease epiphen and keppra. I am desperate now
    For any suggestions now as my poor dog does not seem to get any better even being on all these

  10. bailey 1.3 years old great dane 10.5 stone
    started having seizers 6 weeks ago 1 a week then a group of 4 2 weeks ago .
    next next day started on pexion 2x 400mg twice daily
    no side affects no seizers
    now a very happy dog again

    Hi everyone,
    I haven’t posted for a while but have been following posts.

    Jack was doing well on the Pexion until the start of the year and then the seizures started to increase. Finally we were getting to the stage he was having 4 a month so I took him to see the vet yesterday and she has just got back to me.
    She contacted the makers of Pexion and they have now discovered that if a dog was on KBr (potassium bromide) prior to starting Pexion then he/she should remain on it. We have now resumed KBr so hopefully once Jack’s dose builds up to a therapeutic level we should see a reduction in his seizures. We withdrew the KBr in August after weaning off PB so it would have been in his system for a few months so this is probably why the seizures didn’t increase immediately.
    On a positive note, Jack’s seizures are very short, about 1-2 mins in length followed by 5-10 mins pacing before he makes a complete recovery. The vet hadn’t seen Jack since he has been weaned off the Pb and she was amazed by his altered behaviour. He is so much happier now, his tail was wagging and although he was very excited he was much happier about having his booster.
    I hope everyone is having a happy, seizure-free day.
    Kind regards,

    • That’s really interesting, Murphy was on bromide from last January until August when I swapped him onto Pexion. He only had two fits all last year, but since this January he has already had four, three of which have been in the last month.

      We’ve upped his Pexion, but will see what happens.

      • I forgot to say that we increased Jack’s dose of Pexion from 1000mg x 2 up to the maximum dose for his weight (38kg) which is 1200mg x 2 in mid January and it made no difference to the frequency of his seizures.
        I think the makers of Pexion have only just become aware of this as most dogs that started on Pexion last April/May are only now having issues if they have spent months weaning off PB and KBr.
        I’ll be interested to see what your vet says.
        My vet is also considering referring Jack to a neurologist.
        Kind regards,

        • Murphy isn’t on the highest dose, he is 26kg and is on 600mg twice a day. Vet is going to call m tomorrow to discuss this. The highest dose he can have is 800mg twice a day. I am tempted to leave him on the Pexion and see how he goes if we increase, but am now worried that the Bromide mixes with the Pexion and causes a problem.

          Did your vet say why you shouldn’t use Pexion after Bromide?


          • Sorry, Wendy, I didn’t think to ask the reason why but I’ll wait to see if anyone else has any questions and I’ll email my vet to ask her to contact them again for answers.

          • Wendy,
            After reading your last post I’ve just read my original post and I don’t think I made it clear that Jack is still on the max dose of Pexion but we have added 325mg x 2 of KBr to it. Sorry to cause confusion.

          • Aaahhhhh! Ok, I got the impression that they couldn’t take Pexion if they had originally been on Bromide. So do the makers say that Pexion doesn’t work so well if your dog was originally on Bromide?

          • Hi Wendy,
            Yes, I think that is the gist of it. My vet said that any of her clients’ dogs switching to Pexion in future would have to also continue with the KBr too if already taking it. Those just on Pheno won’t be affected. I don’t know about any other AEDs as I don’t know if my vet uses any others.
            I will try to get answers – just didn’t think when she phoned earlier.

          • Sorry thats not true for Izzy, she couldnt take the bromide anymore as it gave her pancreatitus so it was withdrawn and that was when we heard about pexion so Izzy was on pexion and being weenex off the epiphen.
            Amanda xx

      I didn’t make it clear above that Jack is continuing with the max dose of Pexion but we have added 325mg x 2 of KBr to it.
      What I should have said is that if dogs have been on KBr prior to starting Pexion they should take both Pexion and KBr together rather than withdraw the KBr.
      Sorry for the confusion.
      If anyone has any questions I will get back to my vet and ask her to contact the makers for answers.

  12. I’ve just phoned my vet and asked him to check this out and find out why they say this.

  13. my boy was on both pheno and Kbr when trying Pexion… we had a terrible time as described earlier. The problem with using new drugs is that they cannot give you all the answers… Pexion was only ever trialled on dogs on no other AEDS and was not recommended for dogs with clusters as had not been tested either (not mentioned to my vet when starting us on it). Most people I know with dogs that didn’t cluster started to after starting Pexion, very few people have had results with this drug. The manufacturers representatives here in spain just tell you that the dose is not high enough, my dog ended up on such a high dose it almost killed him

  14. Millie is almost 8 years old and is a Springer Spaniel. She was diagnosed with epilepsy in February 2012. She has been on Epiphen with her dose continually increasing to 120mg x 2 per day. We tried her on potassium bromide but she had terrible side effects including chronic diarrohea so it had to be stopped. Her liver enzymes have increased every time her bloods have been checked so the vet recommended we introduced pexion. She is still on 90mg of Ephiphen x 2 per day. She was only on Pexion for 5 days when she had a cluster of fits so then had Keppra for 3 days. Her most recent fit lasted about 6.5 minutes and she took about 45 minute to really recover. She is due have her liver enzymes checked again next week. I know I have to wait to see what happens but I find ‘waiting to see’ very difficult and I find her fits heart-breaking to watch. We are due to go away on holiday in a few weeks and I really don’t want to leave her.

    • If you read back on earlier comments, it seems that dogs that have been on other medicines don’t take to pexion very well. Ask your vet to read this sites comments. Good luck. Amanda xx

    • Hi, not sure if your dog had clusters before Pexion? But it is not recommended for dogs that cluster – mine does but still they recommended it to me.. he had a dreadful 3 months resulting in him almost being PTS!! In all the groups and people I speak to I have only come across one person that has had success with Pexion they will keep telling you to put up the dose… we reached max and my dog had terrible hallucinations and side effects unheard of….
      It was never trialled on dogs taking any other medication either, so the side effects cannot be guaranteed, I have known people who’s dogs had been on no other medication, had never had a cluster seizure UNTIL they were on

    • Hi, not sure if your dog had clusters before Pexion? But it is not recommended for dogs that cluster – mine does but still they recommended it to me.. he had a dreadful 3 months resulting in him almost being PTS!! In all the groups and people I speak to I have only come across one person that has had success with Pexion they will keep telling you to put up the dose… we reached max and my dog had terrible hallucinations and side effects unheard of….
      It was never trialled on dogs taking any other medication either, so the side effects cannot be guaranteed, I have known people who’s dogs had been on no other medication, had never had a cluster seizure UNTIL they were on this drug.. I would urge you to take your dog off Pexion and find another AED to try alongside normal treatment, there are lots of tried and tested drugs out there to use besides this, I know lots of people have success with Keppra alongside pheno and potassium bromide, not sure what your dog is already on? Good luck whatever you decide

      • Please read from the beginning of all these comments, but also check other canine epilipsy sights, I found s lot of useful info about diet and natural remedies. My research also found that there are 2 main types of idiopathic epilipsy- a brain scan will show if there are any reason fir fitting, those that are undiagnosed with underlying issues are idiopathic. This group seems to be split in two, aggressive and non-aggressive. The aggressive strain takes the dogs before they reach 5 or 6 its as if the fits are learned behaviour that gets out of hand ( there is nothing you can do to stop this so dont blame yourself for not doing your best for your beloved pet. The second passive epilepsy is treatable with drugs or natural methods. I think more research needs to be done by vets, if they pooled information online and listened to owners stories and stop treating our pets like guinea pigs.
        Amanda x

      • Thank you both for your comments. Millie didn’t have clusters as such although she has been known to have a fit in the evening and take a shorter fit in the morning. When she first had fits she would be really aggressive when she came round which was out of character and frightening. However the epiphen has stopped that. I am planning to let our vet see the comments here. Millie is still on ephiphen and pexion and takes Urilin. She is licking her lips a lot (and anything else!) and is starving all the time. She is really cuddly and doesn’t want to walk more than 15-20 minutes. I think even the vet doesn’t know what to do anymore…

  15. Amália Maria Nunes

    I apologize for my bad English. I’m desperate. My 9 year old boxer is taking phenobarbital since january and 10 days ago I (and a Vet) introduce the Pexion. Since 4 days ago has had partial seizures of 10 in 10 minutes, or less. Insted of improving is getting worse.
    I’ m slowly withdraw Pexion, but is no information on Pexion site. She continues to take the pheno and I wanted to finish faster the weaning (?) process. I’m full of fear to withdraw all at once. Please, someone help me.

  16. You can stop the Pexion, you dont have to wean her off that.

    • I would suggest you read earlier postings on this forum. Dogs that have previously been managed on pheno and bromide and then put on pexion need to reduce the pexion slowly and increase other meds. Have you tried Keppra? Please be careful and when your dog is having fits one after the other use an icepack on the head and neck as the fits cause heat which can lead to more fits. I would also recommend reading on canine epilepsy websites, the Americans are using many natural remedies that can be used alongside medicines given by vets. Good luck.

  17. Amália Maria Nunes

    I will read carefully every post. I do not know if there Keppra in Portugal. I will ask the Vet. Potassium Bromide does not exist, the sale was proihbited. She continues with parcial seizures. I’m slowly reduce Pexion. Thank you for important advices.

    • When your dog has a seizure have small towels handy and cover your dogs face sit at its back and be as quiet and calm as you can. If you can get Bachs rescue remedy also called Five flower oil from a chemist or online herbal website, put 4 or 5 drops where you put flea treatment on the neck when you see signs of fit coming. The oil helps calm the dog. Ice packs keep temperature down. If you can get Skulcap and Valerian tablets from http://www.petdrugsonline, I dont know how far they ship to. Hope you are able to find something that helps.

      • Amália Maria Nunes

        Tank you very much. She is improving slowly with the withdrawal of the Pexion. We have increased the dosage of phenobarbital to stabilize her. Continues with parcial seizures, but now are less intende and less frequent.
        Tank you, again, for help and advice.

  18. Our border collie (between 7 – 8 years old) had a cluster of seizures (5 in less than 24 hours) without any prior attacks seen. After the fifth he was totally disorientated and confused. He was originally put onto Epiphen tablets of the lowest dosage. These seizures then stopped. 18 months on and though still no seizures the vet was getting concerned about an increase of liver enzymes in his blood and recommended that we went on to Pexion. We started his full dose of Pexion (400mg) tablets immediately and started to reduce the Epiphen. We did not notice any side effects from the Pexion and some two months on his epiphen is almost three quarters less. He will be off epiphen completely by early May. Once he had got over the initial fits (which took about two weeks) he is as lively and ‘normal’ as any other border collie and so far no more fits. When he is off the Epiphen completely we will have a further blood test done, but so far very pleased with the new drug Pexion.

    • Thanks for that, it is nice to hear a more positive response. We are due to reduce Millie’s Epiphen again tomorrow and I do feel a bit apprehensive. Even on 120mg of epiphen twice a day, Millie still has fits about every 4-5 weeks, so she would be due to fit around next week anyway. Her liver enzymes have reduced already since we first reduced her epiphen which is good news. Fingers crossed!

      Good Luck!


  19. My two year old bulldog had 3 single short seizures approx. 6 weeks apart. One day he had 5 within one day, several hours apart, 2 full seizures and 3 head shaking only. Vet started him on Pexion 400mg twice a day. Was very specific to trying to keep about 12 hours apart and on empty stomach; as instructed in literature. He had one more seizure within a few days of medication starting but so far, two months later, is seizure free. I’ve noticed no side effects at all, thirst, diet or nature. Vet suggests keeping him on the same dosage for the next 6 months to monitor effect and then reduce it to 200mg twice a day because at 22kg he is border line for the recommended dosage. I was advised that we could stop immediately the medication to see any negative effect, because like most people I would rather my little man be drug free, but I’m being patient because the last thing I want is to see another day of fits. I’ve read with interest the above comments and was a little apprehensive about this drug but the vet put him on it because of the fewer side effects and not needing regular blood tests. All I can say is – fingers crossed – everything is going really well. Good luck to all of you, I only wish you all could have had similar results.

  20. We live in the Netherlands. Pexion is very new here. Our doctors don’t know much about it and have no experience. We asked for pexion ourselves to treat our dog with cluster attacks of epilepsy. We now use Pexion for four days. Our dog weighs 9.5 kg and is on 1 tablet in the morning and 1 in the evening.
    He is now free of attacks for over 24 hours, while at first they seemed to increase. But now he seems kind of sedated. His coordination is very poor, he only wants to sleep and finds it difficult to walk. Prefers to ly down.
    Does anyone recognize this. Is this normal? Or is the dose too high although it’s conform what the medication advises.

    • It sounds normal to me. My dog was like this when he first started on Pexion, it lasted about a week then he got used to the medication and was back to normal.

  21. My dog Ben 11 1/2 a Border Terrier has been on Pexion for about 1 month. He was having episodes of trembling and depression, he did not loose awareness, or have fits, and was eating and defecating as usual, he did look confused and in pain hence the reason i took him to the vet. Eventually a diagnosis of a brain tumour. I did not have a MRI scan as it is costly and if it is a BT it would not cure him. Since being on this drug he is so much better, back to his old self and enjoying life. He has had no further attacks he drinks a little more but otherwise he is fine. I take each day as it comes, and treat him as normal. I am just happy to have him as long as I can, especially as his mom is in renal and heart failure at 15, losing them both is unbearable.

  22. Hi – just thought I would post a comment as I found the dialogue “helpful” if not a little scary when I tried to investigate this drug. Winston – an English Pointer and very fit – was 5 when he started fitting – months apart to start and then over the Christmas period they started becoming every 2 weeks. The vet suggested that we try Pexion and although very loath to put drugs into him after having a weekend when he had two within 2 days we started. He started on 1 x 400mg tablet twice a day but a week or so in he had 4 fits in 24 hours which was very scary. The vet upted the dose to 1 1/2 tablets twice a day at the beginning of February and since then no fits which is great. I cannot say he is not affected by the drugs – very hungry at times, thirsty, perhaps a little lack of balance but then he was extremely well co-ordinated – but if I think back to the fitting days then it I have to conclude it is better. We have a problem in that he hates taking the tablets but I cover them in butter which help them slide down – but still makes me feel like the evil witch when he disappears at the same time morning and night before they are due. So to all of you about to start this journey, I want to say that it is bearable and preferable and does work for some dogs. Good luck

    • Our nine and a half year old border collie has now been on Pexion for two months and he is now on the final month of Epiphen – 1 30mg tablet per day, until early June when he will finish completely. (he was on 60mg Epiphen twice daily for over 18 months) We had to change from Epiphen as the vet was concerned about an increase in his liver enzymes. From day one we did not notice any side effects from his Pexion, 1 x 400mg tablet twice a day, neither to date have we noticed any side effects/problems with the gradual withdrawal of the epiphen. Most importantly of all, no fits/seizures either.
      From reading all the comments, it seems that many of the less fortunate animals have been on several other drugs as well as Pexion – it must be very hard but I think that Pexion will work for the majority of cases and I am only sorry that others have not had the success that we have had. Do not give up too soon.
      (when we started the epiphen it took about two weeks for side effects to wear off but it did stop the fits.)

      • elizabeth hilton

        My border collie Maddie who is now 13 has also been on pexion 400mg twice a day for nearly a year. Initially she did very well and only had seizures every month or two. Now she is having them more regularly and sometimes one a week which is very disappointing. I always make sure she has the tablet 12 hours apart and on empty stomach. She weighs 20 kg and has never been on any other medication but Pexion. I dont want to increase her dosage and hope her fits will decrease again on their own. She still plays ball, goes on long walks with our young collie and is a very happy dog. I am convinced that years ago dogs did not have fits and wonder if it something to do with mans intervention to their diet. None of us really know what is in this dried food though I do feed my dogs on veg, veg juice , chicken and odd bits of liver. Her main nuts are Burns as vets do say that it is better than most, but who knows.

        • I was told from a reliable judge of Border Collies that if a breeding line produced a dog/s with epilepsy then that line should not be bred from again. However, if Border Collies (and other breeds) can fetch good money then many breeders will not take any action. Also our Collie was several years old before his first seizure. As in humans it seems that epilepsy can occur at any time and without warning. Again, according to our Vet, Pexion has – as yet – no side effects so it may be worth – with your vet’s advice – increasing the dose which I believe is initially set by your dogs weight. Our collie is on one 400mg tablet of Pexion twice a day, and not always exactly 12 hours apart. We also feed him on dried food as we have done with all our other dogs in the past and this is the first dog we have had with epilepsy. I think we are all learning about it but I do hope your dog’s fits will decrease. Good luck

          • Amanda Kirkman

            It is a problem worldwide and not just border collies but every breed of dog. People are making too much money from breeding dogs and we continue to pay good money for bad breeding. In breeding can cause the seizures and also diet. I am an advocate for feeding raw and my new little collie is a glowing example of all I learnt from my first gorgeous collie Izzy, who was epileptic and despite my best efforts passed over to the rainbow bridge last September. Look on American sights they seem to use every available resource to help their pets including natural remedies. My particular version if the BARF diet is from an american site and includes everything for good mental and physical growth of the dog, its so good everyday I get comments on the healthy gleaming, non smelly coat of my dog. I have fed her this diet from a puppy and would never buy pet food for my Pip, she is what she eats.
            Amanda and Pip

          • elizabeth hilton

            Hi there,

            I did buy my 13 year old collie from a welsh farm and she cost nothing, so I dont think she was inbred, but perhaps she was. I knew nothing about dogs having fits until a year ago when My collie started having seizures at the age of 12, but she was hit by a car at aged 9, so I often wonder whether that was the cause of her fits. I am a nurse and have to say that a dog having a seizure is much more distressing than a human. I do agree though that diet plays an important role in dogs well being, just like it does with humans. We are what we eat. Maddie has a beautiful coat and its still shiny at the age of 13. People do not believe she is 13 plus. So I do feel that her diet is right for her, but will certainly investigate BARF. Good luck to all those dogs on pexion which is the only epileptic drug I have used on my dog.

    • I give attila his pexion with 1/2 small spoon of organic peanut butter. He lines up for it.

  23. Hi, I have been reading how some of you have found Pexion. I have to say and it would appear from previous comments on here Pexion is potentially the cause for my German Shepard Indy’s clusters seizures and hyperactivity. she was on epiphen for 2 years, but due to her liver enzyme changes the vet recommended we wean of the epiphen (gradually) and put her on pexion. I noticed once the epiphen was finally out of her system, she was a lot more alert and energetic. at first we assumed it was because she was no longer on the epiphen. however she begun to then have cluster seizures, so the pexion got increased by the vet. these clusters would last 48 hours. however since last Saturday she has been anxious, hyperactive, cant settle and is having lots of mini cluster seizures or twitching. she has come home today post 2 days at the vets. she is on oral diazepam to keep the twitches a bay and PR diazepam when she has a grand mal. we have now been advised to come off the pexion and back on a lower dose of epiphne, i personally feel that her seizure pattern change is due to pexion, it seems that the clusters begun when pexion was introduced and then became much worse when the dose was increased. Has anyone else had problems with pexion?

    many thanks jo

    • Our Border Collie is now on the last three weeks of epiphen having gradually reduced the dose over a three month period (as above due to increasing liver enzymes) He was put onto Pexion two and a half months ago – one 400mg tablet twice a day. So far no problems but we will monitor closely as his epiphen is reduced/stopped.
      It is now over eighteen months since his last cluster of fits and we were sorry to have to change from the epiphen as they seemed to be doing the job well but obviously at a cost.
      Reading all the comments we now realise that our dog has had nothing like the severity of fits as some of the dogs on here have had and can only hope that the pexion will work for Koda as well as the epiphen did.
      Our best wishes Jo and to all the others, I am sure pexion will work but as ever there will always be some for whom it won’t.

      • Hi Wills,

        Thank you for your response, i really wish you success with the Pexion. i advise once your dog is only on pexion if you notice any hyperactivity/hyper vigilance to speak to your vet as in my experience and others we have found this to be the warning sign of sever seizures etc. After a week of cluster seizures, focal and grand mal, Indy is beginning to settle now we have reduced the pexion. she is back on a low dose of ephien and when she reaches a therapeutic blood level, my vet is advising to come off the pexion completely.

        All the best jo

    • Hi,
      What you describe is exactly what happened to my dog, behaviour change, excitability, worse frequency and cluster fits, the vet increased the pexion to max dose, fits worsened, cluster fits to status very rapidly and he had to have an anaesthetic to stop . Eventualy we had to let go as our lovely dog was gone long ago. I hope nobody has to experience the same and I can only wish that canine epilepsy will get better research…

      • Amália Maria Nunes

        Hi Jo
        You described what my dog has passed. She had parcial seizures all the time. I pulled out the Pexion.
        Sorry for my bad English.


        • Hi Amália,

          sorry to hear you had a bad experience with Pexion too, i Hope your dog is now doing well. Indy is slowly improving. and coming off the pexion too.

          Best wishes Jo

      • Hi Valentina,

        I am so sorry to hear about your dog. I am really concerned that Pexion although beneficial for some dogs, it is a danger for others. I was really worried Indy was going to have to be put down this week, but after a week of focal and grand mal seizures she is now home and on oral diazepam as still having focal seizures until the Epiphen has reached a therapeutic blood level. she will then be taken of Pexion and it has already been reduced and i have seen an improvement not only in her hyperactivity/personality, the seizures are becoming longer apart. Some may say coincidence but i believe it is the pexion and my vet is not going to recommend to anyone again.

        Best Wishes jo

        • Amanda Kirkman

          Dear Jo,
          It looks like dogs that have been on epiphen and bromide for a while maybe over a year, then put on pexion when the liver enzymes increase don’t do well on pexion. I wonder if the research shows how many dogs the pexion was introduced to in trials had been on any medication first. Interesting, I don’t think enough research and information has been given to vets. The paperwork seems to simple – withdrawing the pexion for example is to stop it as it doesn’t affect the liver? Why then have so many of our dogs had unstoppable fits when the pexion was withdrawn that vets have had to sedate them and like my beloved girl after two weekends of having over 30 seizures in a 24 hour period where PTS? More research needs to be done.

          • Pexion was never tested on any dogs that were already on medication for epilepsy… and is not recommended for cluster dogs, although that is not told when trying to use the drug on your dog (not with me anyway) I firmly believe that Pexion has caused some kind of damage to my dog due to the terrible side effects and mega clusters he suffered whilst taking this drug as he is much worse now than ever was before trying this drug.. I would urge people to try more trusted and conventional drugs before trying Pexion!!!!

          • My vet put Izzy on pexion as she developed pancreatitus after being on bromide and epiphen for over 2 years. Initially she was fine, then after 34 days she had her first day of continuous seizures and spent a night at the vets sedated. I took her home the next day as she seemed better at home, more relaxed and I started her on diazepam tablets and had the rectal diazepam for clusters. She had a few fits every day until the following saturday when again she had them none stop all day. I couldn’t stop the seizures and after using 2 rectal diazepam I took her to the vets again, she had a seizure every 2 minutes in the car and her temperature was through the roof. She stayed at the vets until monday when they told me they couldnt stop the fits and put her to sleep as they didn’t think she could take anymore, that was in September 2013. I don’t think enough information had been given to vets about Pexion and it’s effects on our dogs, I hope that people try normal methods and holistic natural methods starting with the right raw food diet to help the brain.
            Amanda x

  24. Hello All,

    I am really driven to find out how many of our dogs have found their dogs seizures became worse once taking Pexion. My dog Indy only use to have grand mal seizures, once on pexion she had clusters seizures, including lots of focal seizures, again only since using pexion. she is now coming off it and i have noticed improvement already. PLEASE if your dogs seizures appeared to of become worse on Pexion i am going to contact Pexion company directly and express concerns as this is awful for our dogs to go through and us to witness.

    Many Thanks Jo

  25. My dog had managed to go 11 months without fitting, my vets advised to change from epiphen to pexion. not only did it not work my dog now takes 3 times the previous medication and is still fitting. I was assured the drug was proven before starting the course. only to find out that the drug does not have effect if previous medication for epilepsy had been prescribed

    • So sorry to hear about your dog, yet another one into the breach. I think more vets should be made aware of what dog owners are finding out on this forum, they may not be so quick to change medication and only prescribe pexion to dogs first before the traditional medicines. Good luck and I hope you find a balance again for your dog.

    • elizabeth hilton

      Hi everyone, My dog maddie has been on pexion for 10 months. Initially her fits reduced hugely after a few weeks on 400 mg of pexion. Now she has suddenly started having fits every 2 days. I then increased pexion to 600mg causing Maddie to become so hungry and agitated that I have now after 8 days decided to reduce her to half a tablet twice a day. As yet i dont know what the outcome will be. In our vets practice there are only 3 dogs on pexion, most seem to be on epiphen phenobarb or bromide. To date, pexion is still a very new drug and having been very happy with it initially, wonder if its now causing more problems. maddie has become glazed of late and not herself at all, constantly starving to the extent that at the age of 13, she tries to eat food from the counter which she has never done before. I think the drug is now causing hypoglycaemia so have to give her huge spoonfuls of honey to calm her down and quell her hunger.

      I will let you know how she progresses. All the best to all of you,


  26. Hi Everyone
    I have a 3 year old lab collie X who has recently started medication; 400mg pexion twice daily
    First seizure was in Aug 2012 and vet advised to keep a diary on any future seizures.
    Seizures slowly started to become more frequent and after having 3 seizures last Friday he was taken to the vets where he stayed over night and was given diazepam and they started him on pexion

    Most of his fits seem to be related to anxiety. If we were packing to go away this would cause a fit…..if we were out on a walk and he felt threatened by another dog he would have a fit. There was no common time or place – it could happen any where and with no warning

    After doing some research it seems like there is a lot of negative feedback around this drug. The vets where we are registered didn’t seem to discuss all options avaible to us and I am not even sure of what tests have been done with blood etc. All we were told is that when bloods were taken on Friday the only thing they found was a slightly reduced glucose level which is apparently common after seizures? He also have a elevated temperature
    We don’t know what else was tested for as I have read some where about thyroid levels being out can cause seizures?

    What is it that vets can look for by testing blood? I can then ask if this was tested when bloods were taken?
    It was briefly discussed that an MRI could be done to rule out other reasons as to why he is fitting. Nothing else has been mentioned about this – is this something you would recommend to do?

    I can’t help but think pexion was pushed on us without much discussion of other options and now starting to think we may have made the wrong descion by agreeing this was the correct treatment
    Our dog seems to be very ‘drunk’ like and wobbly on his feet. He has also started to drink a lot more water but seems to be getting better every day but still very sleepy. He went for a walk today and seemed to be his usual bouncy self when he was out

    I have briefly looked at diet change and even a homeopathic vet with possibilty of accupuncture as a treatment?
    Has anyone had any success with this?


    • Emily
      Our Border Collie started fits without warning just over 18 months ago – he was 8 years old then. He was put on a course of Epiphen which while stopping the fits can cause liver damage and we were advised to have regular blood tests – this we did but over the 18 months liver enzymes steadily increased which if left unchecked would cause liver failure. We started immediately on Pexion (1 x 400mg tablet twice daily) and gradually reduced the epiphen. He is due to come off this completely in three days time and then will only be on Pexion. Since he started both these medications he seems to be drinking more and can – at times – seem more ‘hyped’ than usual but apart from that he is fine though for the epiphen it did take a week or so for him to get used to it – but most importantly NO fits!
      I also wonder how many other dogs are on Pexion with little or no side effects – these will be unlikely to contribute to forums like this ( their owners I mean!). We found it most distressing to see the dog in seizure as I am sure anybody would. Don’t give up too soon on Pexion, ask your vet what they look for in Blood tests and if you are still not given full details I would consider changing to another.
      Good luck

    • Hi Emily,

      My Lab, Jack, has been on Pexion since May 2013. If you go to the top of the page you will see my early comments. Jack had been on Epiphen and Libromide before trying Pexion and although he was a bit wobbly for a week or so, once that passed he has been fine. He still has seizures, and we recently reintroduced the Libromide because they were getting quite frequent again (found out that if a dog has been on Libromide BEFORE starting Pexion then they must remain on it). I’m hoping that once the Libromide reaches the therapeutic level it will work with the Pexion to reduce the frequency of seizures to fewer than 1 per month (currently 2 or 3).
      The last thing I want to do is put Jack back on Epiphen because he was so dopey on it he was just existing and didn’t really enjoy life like he does now.
      I hope your dog will be OK on Pexion too.
      Fiona & Jack

      • My dog is on 600mg twice a day. He was on Bromide for about 7 months before the Pexion which he has been on since August.

        He is obviously one of the lucky ones as he hasn’t had a fit since mid-March and apart from initially being a bit wobbly, he now has no side effects at all.

  27. hi guys my vet has today suggested a change from 2mg/kg of pheno’s to pexion, the only reason being the effect of phenos on liver, phased in over 4 months. reading here has panicked me – she is a totally blind 3 year old wolfhound – the side effects when first on phenos were awful, she got them all and i had to literally hold her up for 2 weeks, but she is pretty stable on a relatively low dose. we will do ablood test before the change – if liver function is normal – well any updates on your progress with pexion?

  28. Since 03.02.14 my dog Theo has been taking Pexion rather than the Epitaur I had him on before. The frequency of the seizures is slightly less but their duration longer,all 3 since then having been clusters.
    The vet has now suggested increasing the dose to 2 tablets per day, which is half a tablet more than to date. My dog is a Labrador Retriever weighing ca. 30 kg and will be 3 years old in July.

    We have had to administer Diazepam 10mg rectally during these cluster seizures. In the past chemists have told me that there is no difference between the medication for dogs and humans other than the price. Would it be okay for me to try to buy the human rectubes as they cost a third of the price quoted by the vet?

    • Dear Susan,
      You can get all your medication either at a chemist or for animal medication from If you need a prescription your vet should issue on costing between £5 and £7. If you pet is not insured these are where I would buy from.
      Love Amanda x

  29. My 18 month old dacshund suddenly started having seizures about three weeks apart and lasting for a short time, usually 1-2 minutes. After various blood tests which all came out negative for any disease, the vet suggested Pexion which hasn’t made any difference so far, in fact yesterday he had two fits in a 24 hr period, so I’m wondering if it is the Pexion causing an increase frequency. He is not on any other meds, has Royal Canin dog food usuallly, but am now trialling something else as RC contains maize which I hear is not good for dogs with seizures. Heart breaking to see him fitting and not being able to help him. Not sure whether to continue with the Pexion or not. Am out of my mind with worry.
    Please can anyone let me know their experiences with this drug.

    • Susan – I agree it is most distressing to watch a pet having seizures. Our 10 year old Border Collie has been on Pexion now for over three months having been weaned off his previous drug Epiphen. So far he has been free of seizures and apart from being a little more ‘hyped’ than usual and a slight increase in his drinking all seems well. You do not say how long your dog has been on Pexion – but I think before you change/take him off Pexion speak to your vet or get a second opinion – perhaps a different vet/practice and ask how many dogs in their practice are on Pexion and what if any problems there may have been. Good luck

      • elizabeth hilton

        My border collie has also been on pexion for nearly a year now, she is 13. We know that pexion is a new drug and still in its early stages of complete effectiveness. I have noticed that vets seem to know little about the drug and very few dogs are “on it” Most vets seem to use the bromides, phenobarbs, epiphen etc. The pexion leaflets state there are few side effects and the drug can be withdrawn at any time. I did wean maddie off the drug completely for a week. She became much worse after 4 days and developed cluster seizures so i would not advocate that anyone withdraws pexion completely. She also now has slow heart rate with extra systoles and every now and then her back legs give way. Between times, she is fine. Drinks a lot, is permanently hungry and has minor tremors in her legs. She also has a tendency to lose bladder control and is on hormone treatment which has helped. I cannot bear the thought of putting her down while she still has a good quality of life. More and more dogs appear to be having seizures, I have to wonder why.


        • Dear Elizabeth,
          My partner and I where saying the same thing about the number of pets having epilepsy and fits. I think it is indicative of todays society. Some people are money driven and not bothered about repetitive inbreeding, then you have food manufactures making all this cereal based stuff they call dog food. I promote using a recipe for BARF especially developed in America for epileptic dogs, but brilliant for any dog. You are what you eat certainly applies to my dog, I get asked about her diet daily as she positively gleams. My previous collie was epileptic and started out on epiphen and bromide, we tried pexion too (my comments are earlier entries on this forum) after 1 month on pexion with no fits, she started having clusters every saturday after trying to stop the pexion, she had upto 30 fits each saturday and spent the last 2 sat evenings at my vets who sedated her to try stop the fits. She was put to sleep on 1.9.13 as we all agreed so many fits and no way of stopping them was no good for her. I think more people need to get their vets to put pressure on for more research into the withdrawing of pexion in dogs and find out why some dogs have more clusters during this stage.
          Good luck
          Amanda n Pip

          • Hi Amanda
            My 2 year old, 9kg JRT started having fits 2.5 months ago, 1 every 3 weeks then yesterday had 2 fits in 10 hours. Terrible to witness, they last for about 1.5mins, and he takes about 2 mins to stabilize, and seems fine after that. The vet has decided to put him on meds today – 1 x 100mg Pexion morning and night (I will be sure to spread at 12hr intervals). I am very interested in the diet you mention – BARF. Please could you let me know more about it, where I can get it (online perhaps?). I live in Cork, Ireland. I am so worried after reading all these posts, but he has not been on any other meds, so I am praying that Pexion will work for him. I will update these posts so that all readers can benefit.

          • If you find me on facebook or give me an email address I will let you have the diet details. I would appreciate any feedback and photo’s showing any improvements to the condition and general overall well being of your dog.

          • elizabeth hilton

            Hello to you all,

            I had to have my lovely collie dog Maddie 13 put down last monday. I think it was the saddest day of my life and I miss her so much. She was always with me. In the end I could not bear to see her excessive hunger, her stumbling her confusion and so many mini fits towards the end. I have another collie of one who belongs to my son and he seems fine so far. If he develops fits in later life I would never have another dog. I have said before on this forum that years ago dogs did not appear to have fits. I grew up with dogs as a child, the word FIT or EPILEPSY was never mentioned. The dogs had family scraps, bones from the butcher and both lived a long healthy life. Since all this dried food has come onto the market, I do wonder how good it is for our pets. Whatever the manufacture says, all these nuts are full of preservative since they have such a long shelf life. I have since started giving my young collie scrambled eggs, porridge oats, bananas. shin of beef, mince beef etc bones from the butcher and he has had no ill effects.

            I think if we and our pets ate more healthily and avoided the ever increasing preservatives in our foods, perhaps we would all feel better and live healthier lives. Good luck to all of you who have pets with fits. It is so distressing both for the dog and the owner.


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