I do not know that this surgery is available yet
for dogs, or whether or not there are any canine neurosurgeons who would perform it, but if it does exist, my guess is that it would still be cost-prohibitive for anyone but the wealthiest pet owners or people who have pet health insurance.
A change in appetite is a common side effect of phenobarbital. Some dogs eat less and have to be cajoled into eating, others become voracious and can't seem to eat enough.