Phenomav Side Effects

[odie]

Fristy, I have read the entire topic below with the title "my dog just had a fit or a seizure" and it was very helpful, however I really need anyones experiences with regard to the side effects of this drug. My dog started displaying symtoms of "fly biting" lask week. The vets diagnosed focal seizures and started him on phenomav straight away. We have been to the vets 3 times since then due to dog developing first a tremor, then weakness in his back legs which comes and goes. Sometimes the weakness is just a wobble, other times he can't stand up. The weakness symptoms started after we doubled his meds and have been getting worse all week. He will be getting a CT scan next week, but from my own observations I'm convinced that the medication is the cause of the weekness (its worse after giving him the meds and then improves a bit until i give him the next dose). Everyone seems to agree that being lethargic is a well known side effect, but what are peoples thoughts or expereinces on mild to severe hind leg weakness that comes and goes?

I hope this post makes sense, I've been up all night with the dog.

[*Bella*]

Kayla has had poor coordination since she was a pup, but the pheno made it a lot worse when she first started taking it. She was started on one tablet twice a day, but she could barely walk she was that unstable. The vet did warn me it might affect her while she got used to the drug, but after nearly a week of having to help her get up in the mornings and her falling over all the time, I asked the vet if I could drop the dosage down. So we put her on half a tablet twice a day instead and after a day or two she returned to her level of coordination. Thankfully when it came time to do the blood test, she did have a therapeutic level of the drug in her system and she's been seizure free since.

If your dog has only just started taking it last week, maybe he just needs more time to get used to the drug? Good luck with the CT scan, hope it gives you some answers.

[Staffy-Lover]

Yep the hind leg weakness is a well known side effect. Some dogs do get progressively better as the drug settles in a bit.

My boy is on this drug but doesnt have these side effects so i can't tell u alot. But don't panic.

I would PM Puggles as i believe she would be the best source of info on this particular topic for you.

good luck

[~Anne~]

Phenobarbital has, as a side effect, ataxia (hind leg weakness). I am very surprised that your Vet didn't explain this to you when you mentioned your concerns about this. Other side effects are lethargy, restlessness, excessive hunger, urination and thirst.

I have a Pug, and as you may or may not know, Pugs have curled tails. Due to the Pb, Monte's tail is rarely curled as the hind leg weakness and lack of coordination extends obviously to the tail. I have to have a bed on the floor for him as well as his lounge as sometimes he simply does not have the strength in his hind legs to jump up on the lounge.

We also have found that his lack of coordination and general weakness causes him to drag his feet and this wears down his nails on his front feet to the degree that they bleed after taking him for a walk if there is a lot of ashphalt or concrete walked on.

PB takes up to 3 months to stabilise in a dog's system so be patient and do not expect anything to change overnight. Your dog's system will adjust itself over this time and the side effects will be far less noticeable as the weeks go on.

A word of advice on the CT scan. Epilepsy can only be diagnosed by elimination. Unless your dog actually has a neurological disorder that is causing the seizures (ie like a growth on the brain or head trauma) then the scan will not show epilepsy. The only time a scan is advisable or worth the cost is if a disease or other disorder is suspected. A specialist will perform a basic neuro exam before suggesting a scan. They will test for any other neurological conditions present such as a lack of symmetry in the face, lack of coordination (not caused by medication) and other simple physical tests.

Epilepsy is diagnosed when there is no know cause of seizures.

Many other conditions however cause seizures. Blood tests are usually the first tests and are by far the most common tests performed to determine the cause of a seizure.

How old is your dog? What breed of dog is it?

[~Anne~]

One more thing I feel I should say; Pb MUST be given 12 hours apart. The timing is vital as the pheno only remains affective for 12 hours. After 12 hours the effect it has on the neurons that stop the siezures drops rapidly.

It is VITAL to ensure it is always given every 12 hours (or as close as possible to this) to maintain seizure control.

Also, you should routinely check your dogs liver as the long-term effect of Pb is scarring of the liver. Have your dog's liver tested yearly whilst on Pb.

I hope this info helps.

[odie]

Thanks to everyone who has replied.

I'm now administering the drug every 12 hours. I'm happy to say that I haven't seen a "fly biting" episode in the last 2 days and his hind leg weakness has improved to the point where we can go for a walk and he is now just a bit wobbly.

Its unfortunate, but my vet specifically said that the hindleg weakness was not a sign of the drug but rather that my dog was getting much worse very quickly, hence the CT scan was needed ASAP. This of course sent me into a spin and a search for more info last weak and this site has been a great help. Of course I know that i could be wrong and the vet right but I'm hoping in this instance that its the medication. If, on the lower dose his weakness continues to improve (or he remains fairly stable) then we will wait to do the CT for another week or so.

Thanks again.

[~Anne~]

Which state are you located in?

I recommend visiting a specialist with your dog. Most Vets aren't highly knoweldgeable on the finer points of epilepsy and neuro disorders. If you are in NSW I can recommend Dr Georgina Childs from the Veterinary Specialist Centre, North Ryde.

Consults are much higher then a normal Vet but you are paying for speacilist treatment and advice and the consults are very thorough.

[odie]

I'm in rural north west Vic and would you believe 6.5hrs from Melbourne!

My dog started flybiting again last night which is a bit depressing, so we have upped his medication just slightly to see if he stops again.

If anyone can recommend a specialist vet in victoria please provide details. I'm sure i can get a referral from my vet to see them if needed.

[~Anne~]

I would strongly advise against playing around with the Pheno without consulting your Vet.

If the Pb doesn't work on its own another drug or two can be addd to the mix.

Monte is on both Pb and a drug called Potassium Bromide (Kbr). He still has clusters but they are fewer then what he would have if he wasn't medicated.

Before increasing his Pb I would recommend having his levels tested. The test wil tell you if the drug is at optimum levels. If it is and he is still experiencing siezure activity then they can add Kbr or another drug called Keppra.

When a dog first starts on Pb they should have their levels tested within 2 - 4 weeks and then another 3 months later to check for optimum levels.

[odie]

Its ok, i've only changed his dosage with the vets advice.

He's actually in at the vets today to get his levels tested. Its only been 10 days since he started on the drug and his dosage has changed 4 times. Do you think its to soon to be tested?

Hes still zoning out and fly biting a bit and is also panting (not excessively but its noticeable). I suppose i'll just have to wait and see what the vet says today.

[~Anne~]

How old is your dog and which breed?

10 day is pretty quick but at least you will get some indication.. although it won't be clear due to constant adjustments.

The zoning out will continue more then likely but it will depend on high his doseage is. Monte often zones out. A few calls of his name and he tunes back in though.

[odie]

We believe he is a Keeshond X prehaps with a German Shepard, now 5 years old. He had been surrended to the Pound as a 2 year old due to behavour/disipline issues. We actually had to send him off to be professionally trained for 2 weeks after trying ourselves to get him to learn some basic obedience. It was worth it though. He is a beautifully natured dog, everyones pal, not a mean bone in him and very trainable now.

Happy to say that he is about 90% his old self and is running and jumping with only a few wobbles when we are playing and the occasional slip.

He has packed on the weight though and really needs to lose about 5kg. I've switched his diet the "Avanced" range, but thinking of trying the BARF Diet, do you feed anything special?