My 1st Golden had the same after 1 year & had grand mal seizures all his life, even with 5 grains of Phenobarbital per day. They increased each year until he would have as many as 17 withing a half day …. age 4 or so …. finally tapered off at age 7. There is no cure I know of. I worked with the head of Neurology at UC Davis small animal clinic. He lived to 10 & died in 1989. I’m sure there are many improvements since then. I seem to recall trying a similar liquid but it was tough to give him so much of it …. he was a very large dog at 96 lbs. It sounds like you are having success with the liquid, so I’m thrilled that your shepherd is doing better. Its not curable & he can live a good life with epilepsy. Wish you all the best.
Marci Hill