Lost of control of back then front legs

[JakesOwner]

My 8 year old Lab has been losing control of his hind legs for several months. It finally got so bad we had to take him to the vet. She thinks he is having seizures so she put him on Phenobarbital about a month ago. He has been getting gradually better. Seizures are less frequent, less severe and don't last as long. Today for the first time he lost control of one or both (not sure) of his front legs. Could this be a seizure or reaction to the Phenobarbital? BTW his x-rays of his bones/joints were fine.

Thanks

[Justine Lee, D.V.M., DACVECC]

I'd recommend videotaping this "episodes" so your vet can see if they are truly "seizures" or not. Most seizures result in loss of bowel movement, urination, loss of awareness or consciousness, paddling of limbs, etc. Just losing weakness in the back legs isn't "classic" for seizures - even partial seizures.

I'd recommend having a veterinary neurologist evaluate him, as his breed is really predisposed to degenerative myelopathy. Yes, bulging discs, tumors, etc. can also cause similar signs, as can a low blood sugar. If blood work and potential x-rays of his pelvis, back, and chest are normal, I'd have him evaluated by a specialist!

[Kimberly Coyner, D.V.M., DACVD]

I agree with Dr. Hurley's recommendations, and I would add that in addition to epilepsy (an electrical disorder in the brain), seizures in an older dog can be a symptom of brain inflammation or tumor, liver disease, kidney disease, low blood sugar due to a pancreatic tumor, etc. Weakness in the hind and front legs can also be a sign of a problem wiht the spinal cord in the neck area, such as a bulging disc or tumor.  If all of his labwork was normal, if his phenobarbitol level is adequate and if his neurologic symptoms progress, then evaluation by a veterinary neurologist is the next step.
Good luck,
Kimberly Coyner, DVM DACVD

[Brian C Hurley, D.V.M.]

Sorry to hear your pet is having issues with seizures.  Phenobarbital can make pets sedate over the first few weeks of treatment until the body adjusts to the dosing.  Typically, I would recommend checking phenobarbital levels at this point to make sure the dose has achieved their therapeutic levels.  If the levels are too low, the dose may need to be increased to control seizures better.  It the levels are too high, the dose will need to be decreased.

Please remember, phenobarbital will reduce the number of seizures but may not stop seizures all together.  There are other antiseizure medications that are available if phenobarbital does not control seizures adequately.  Also, liver values should be monitored.

Hope this helps.